On hidden link you see a view for the CPT "Anonce Post".
The posts are from users who use a Form.
When published, it is attached to the wrong template.
I thnik that this problem occured since I removed Views plugin and installed Toolset Blocks.
Durning testing on my website with a similar post form and content template, I couldn't reproduce this issue.
I used the check for updates button at WP Admin -> Plugins -> Add New -> Commercial and noticed a number of important updates for Toolset are still pending on your website.
( screenshot: hidden link )
Please update all these Toolset plugins and then test the form again. If the issue persists, I'll need a clone/snapshot of the website, to investigate this on a different server.
( ref: https://toolset.com/faq/provide-supporters-copy-site/ )
I managed to download the clone from the website using the Duplicator Pro plugin.
During testing, I couldn't reproduce this issue either on your website's clone or on the actual website.
I used the form "Annonce aanmaken" on the page "Annonce aanmaken voor Vraag en Aanbod" to add a new post "Test post title".
( you'll see it in the list of "Aanbiedingen" posts in the admin area )
Next, I checked that post's edit screen and noticed that the "Annonce Post" content template was properly assigned to it.
( screenshot: hidden link )
Can you please test this again and let me know the exact steps if you're still able to reproduce the issue.
I think the confusion is caused by a little change in how the content template field looks now. A few months back a new feature was introduced through which you can assign multiple content templates to posts, based on conditions: https://toolset.com/lesson-placement/lesson-placements-1621067-2019391/
When that feature was introduced, the design/look of the content template selection field was changed. As for the content template assignment part, it is working correctly, and in my screenshot from the last message, you'll see that the "Annonce Post" template is showing, under the select field with "template dynamically assigned".
( screenshot: hidden link )
Since, this theme uses a non-conventional and non-standardized approach for showing the content on single post pages, Toolset's dynamically assigned templates are no longer compatible with it.
As a quick fix, you can replace the code at line# 189 in the file named "single-aanbieding.php", in your child theme's folder "enfold-BZ" and the assigned content template will start showing, on the front-end.