I'm using Joomla 3.7.2.
I am not able to save any changes to my current modules or create new modules. I only make edits to my site in the administrator backend (siteurl.com/administrator).
Save and Save&Close both do not work with my site's modules anymore. Specifically, opening a module and clicking Save or Save&Close checks-in the module without making any edits. I also cannot make new modules or check-in modules from the list of modules.
What I can do
From the listing of all modules, I can open(edit), duplicate, publish, unpublish, and delete modules. If a module is checked-in, I can check it out by clicking on the lock.
However, I am not able to save any changes I make to modules.
This is quite strange because I am able to save changes to all other areas of my site (settings, users, menus, articles, categories, components). It is only modules that has an issue.
What I have tried (in no particular order)
I have tried restoring previous backups of my site (from when I was able to edit modules). Specifically, overwriting existing files and directories in my public_html root using Filezilla and then restoring the database backup in phpMyAdmin.
I have checked all global configuration settings, including settings for the Modules component. Administrators and Superusers are both allowed to configure ACL & options, Access Administration Interface, Create, Delete, Edit, and Edit State for Modules.
I have checked user group access levels. The account I am using belongs to the administrator and superuser groups. I have tried creating new administrator/superuser accounts.
I have tried clearing Joomla's cache and expired cache.
I have tried clearing my browser's cache (I am always in Incognito mode so I simply close my browser and start a new Incognito session).
I have tried both Chrome and Firefox (latest versions).
I have tried Fix on the Joomla database (Joomla backend->Extensions->Database->Fix).
I have downloaded the full stable release of Joomla 3.7.2 and overwritten Joomla's core files through Filezilla.
Recently, I have been having issues with two extensions (Joomfuse and Advanced Module Manager).
I have tried disabling those extensions in combination with the above things I have tried.
I have tried uninstalling those extensions in combination with the above things I have tried.
I have tried reinstalling those extensions in combination with the above things I have tried.
Besides those changes, the only other change has been the installation (and removal) of Akeeba Backup.
I have contacted Joomfuse and Advanced Module Manager's support. While both teams are very helpful and responsive, so far, they have not had any success in helping resolve this issue.
If it makes any difference, our site
If anyone has any insights or possible suggestions as to what may be the issue, that would be much appreciated.
I am a recently graduated college student (undergraduate computer science minor) and feel very in over my head. None of my coursework covered websites. I have only had an introduction to data structures, software engineering, and program design. Over the past few months, I have learned about Joomla, Wordpress, and website administration through Google and trial-and-error.
Thanks in advance for any guidance that may be provided.