I have a weird scenario where I am trying to edit my global template preferences. I change a simple dropdown or field, hit submit, and get a successful indicator (the green icon at the top of the screen) but the field has not changed. I output all template debugging and there doesn't seem to be any errors, but all changes are reverted to what they were before. I verified file permissions on database.php and config.php were 666. Any ideas why this might be happening?
I would suggest checking your config.php file and see if any of those global template preferences are explicitly set in your configs. If you are using FocusLab master config, I would check config.master.php and your individual environment configs.
I suggest reuploading your Themes directory. It's possible something is missing or corrupted.
Also, look for JS errors in the console that might be causing an issue.