I have a site that has been up for some time and functioning without issue.
There are a number of products which have 10-20 custom options configured in admin. I logged in recently to discover that I can only see the last 4 custom options configured for any given product. All of the custom options are still appearing correctly on the frontend; it's only the backend where they're missing. I checked the database and all the product option entries still exist and appear to be in order. I've cleared all caches and reindexed everything, but there was no change.
Unfortunately I have no idea when the problem arose, and all of the product entry and configuration was done for the site 7-8 months ago. I've made numerous changes to the site and installed a couple extensions since then.
The only other thing I can think to check at this point is to see where the options are being pulled for the admin view and try to see what's going wrong, but I'm having trouble figuring out where to start. Can anyone point me in the right direction? Site is on version 1.9.2.3.