Settings in Admin get dropped, will save temporarily, hours later are reset/gone

Question

I have a situation on my development site, where all of a sudden lately, some things I save in the admin, aren't "sticking" around.

Some of the settings that won't stay:

Template routes: I will set up some routes, they'll work for a while, hours... and then I'll start getting 404's when trying to access these routes. I go back into the admin and my routes are suddenly gone.

Structure settings in entries: I'll assign a template to an entry, again this will work fine for a while, hours etc, and then suddenly I'll start getting 404's for these entries. I go back to the entry and the template is no longer assigned to the entry.

Template settings: I'll set php settings to "Yes" and parsing to "input" - php will be working fine in my template, and then a few hours later, BOOM the settings are back to the default.

I have verified with our sysadmin that the DB looks in good shape, and we're not seeing any php or other errors. I have debugging on etc.

Answer 1

This actually turned out to be an issue with the plugin "Template Sync" - EE support helped me figure it out (thanks Robin!).

Narrowed it down to just a templates issue, and found "Template Sync" was deleting my templates from the DB. And was fine to uninstall since it was no longer needed after EE 3.

Uninstalled the plugin, and everything is working fine now!