PHP fatal error & problem with categories/taxonomy after WP v.6.0 update

After updating WP to v.6.0 (translated/greek language version), I’m facing a posts categories/taxonomy problem.

Things I’ve noticed about the problem, in the official website (live) & clone (for testing purposes version) as well:
– Visiting certain posts categories with existing posts (e.g. index.php?cat=5), I receive NOTHING FOUND message, which is not true (posts exist, I can browse them connected as author or admin user). The issue affects exactly the same nine (9) categories IDs with reference to tbl_terms MySQL tables (live & clone website).
– In wp-admin Posts Categories section, the same categories seem to be not editable. I’ve also found that I can change the URL of an editable Category (/wp-admin/term.php?taxonomy=category&tag_ID=69) replacing the tag_ID with a so-problematic category ID (e.g. 6), opens the so-problematic category edit form, but after updating, the category updates itself in the category list with a new ID (e.g. 73), different than the initial ID!! At the same time, opening the posts URL of the so-problematic category using the new ID (/index.php?cat=73), the previously shown NOTHING FOUND message is not shown anymore & posts re-appear!!
– Connected as author or admin user, visiting the posts page, I can see all my posts, but the posts related with one or more of the so-problematic categories, seem to not have any category at all. However, if I edit the post, the relation with the so-problematic category is shown as it should! Updating the post, seems to restore the category.

I should also mention that the WP v.5.9 worked just fine before updating to 6.0.

Concerning the PHP fatal error, using WP backend connected as author or admin user, I receive critical error message, quite often & almost in a recurring way. Inspecting the log file, the error contains “mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 15728640 bytes exhausted (tried to allocate 65536 bytes)”. The URL mostly referred is /wp-admin/includes/admin.php, line 35 specifically. I informed & contacted hosting provider, they answered me the below memory settings
memory_limit = 256M
max_execution_time = 300
upload_max_filesize = 100M
post_max_size = 100M
max_input_time = 120

& suggested me to further check WP code.

I would appreciate any help/advice about the problem & possible ways to solve or best practice to handle it.

Many thanks in advance.

Kind regards.

• This topic was modified 1 year, 10 months ago by tkatsaros. Reason: Error details

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