Hello, Simon, I am Beda, we should know us already 🙂
I am sorry for the mess here, this is a big misunderstanding that was the cause of this huge delay.
I just recognised, now being assigned to your Ticket here, that you talk about Taxonomies and not about Fields.
But, the Issue (your Ticket here) was added to a list of an internal Ticket where we handled a Problem with FIELDS (checkboxes) and that has been fixed, and that is as what your Ticket has been reported to 2nd Tier (Instead of issues with the taxonomies).
This is, of course, no excuse nor explanation, but I want to explain why this is not fixed yet.
It may help you to understand why the delay.
And I do apologise this, you reported the correct problem in the correct way, long time ago, and it's our complete fail to not have addressed this.
From your first post, the old thread, I gather:
I have a custom hierarchical taxonomy on a CRED form - displaying as checkboxes. If I select or deselect terms and save, it works fine - until I deselect the last term. When I do this the changes are not saved.
For example, if I have 3 terms selected, deselect 2, save, then only 1 term is set. However, if I have 3 terms selected, deselect all 3 and save, then all 3 remain selected.
I do have the latest version of all plugins installed on my site.
It is a very simple report, so I wonder how it came to be Checkboxes Fields all of a sudden 🙁
But anyway, currently, on a fresh install I cannot see this.
But I am sure I miss something and am now deploying your Site Locally, and will be back ASAP, with a solution for good.
Thank you for your long term trust and patience 🙂