Well, as the mail log shows, it sent the emails as I tested the forms with that setting off.
I tested again now and it did not work, the only I can think of is that things changed either while I made tests or after.
I cannot confirm an issue when it's behaving differently every time we try it out. We cannot fix issues in Child Themes.
Also the interruptions on the server (sometimes it never loads the pages) may even break the wp_mail used to submit the notifications.
I could try again confirming this on a infrastructure we can control.
Can you send me a copy of that new test site eventually?
Note that if the issue happens only on the child theme, or the server, we cannot fix it.
But we can assure it is really an exception first.
I apologize asking again for this however there seems no other possible approach to pin down this bug.
That is not a Duplicate, it's a copy of the FTP, and it missed the most important part, which is the Database.
I also see in it's Error log a long row of errors, printing here only the ones from 23rd april (the list is remarkably longer):
[23-Apr-2019 00:00:05 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 00:00:05 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 01:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 01:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 02:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 02:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 03:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 03:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 04:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 04:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 05:00:02 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 05:00:02 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 06:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 06:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 07:00:02 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 07:00:02 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 08:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 08:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 09:00:02 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 09:00:02 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
[23-Apr-2019 10:00:03 UTC] PHP Fatal error: Can't use method return value in write context in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/wpai-toolset-types-addon/libraries/toolset-fields/fields/fieldCheckbox.php on line 50
[23-Apr-2019 10:00:03 UTC] PHP Fatal error: Class 'wpai_toolset_types_add_on\toolset\fields\WC_Log_Handler' not found in /var/www/vhosts/radioverulam.com/httpdocs/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php on line 19
What is wpai-toolset-types-addon?
We do not produce any such plugin.
However, to see the issue, to replicate it eventually, and to fix it, I require a Duplicate of this website, and if this is not possible, then the FTP as provided above can help but I will need the exported database as well, logically, otherwise this problem cannot be replicated if existing, since with the FTP files alone, I would not replicate the actual site.
Can you either send me a duplicate made with https://toolset.com/faq/provide-supporters-copy-site/ or, if this is not possible, an exported ZIP of the SQL Database?
Thank you!