Unreal 4.7, FMOD loses all references to bank and all generated files when regenerated, only works on a second load of Unreal

I am havign a strange issue that is affecting my team and a large project we are part of.

We have “FMOD 2.02.15, 64bit, built #134211” set up and have been using it for several months with varying degrees of success with “Unreal 4.27.2”. We went the route of versioning our .bank files through perforce, which are stored in FMOD/Main/ in the project, and then allowing Unreal to generate all other project files locally on everyone’s machines in the FMOD folder as per the FMOD documentation.

This worked well for us initially but we are now running into a strange issue. The easiest way to illustrate the problem is when a team member syncs the unreal project at the latest revision and loads up the editor. It generates project files from the .bank files as expected, but once complete, Unreal has seemingly lost ALL FMOD event/bank etc. references in all blueprints. Reloading banks doesn’t help. We get an initial error message… unable to load asset lookup, unable to load bank lookup. The only fix is to close the editor, and reopen it, at which point all the references are perfectly fine, and the errors don’t reappear.

After some testing it appears that the problem stems from the bank.uasset files being regenerated. deleting just the events folder, or buses, private integration data, etc all seem to regenerate fine. Deleting the banks folder where the bank.uasset files are stored results in lost references unless the project is closed and reopened a second time. Deleting the events folder AND the banks folder results in even more references being lost. Luckily it seems to be temporary unless someone specifically goes into the blueprints and saves them with the missing refs, which then saves them in that state.

The team on this game is very large and the same issue affects everyone. While it is possible to get around, it has caused us quite a few misunderstandings and confusion among the dev team and us on the audio team as well. Any help would be greatly appreciated, I can provide some error screenshots with blurred-out paths and game names if necessary.

I have not been able to reproduce this issue with your versions. Are you using a launcher build or source build of UE4.27?
Just as a test (not suggesting this as a workaround), if you delete the generated Banks directory and rebuild generated assets through the commandlet before opening the editor, does that allow it to open with unbroken links?
If you could please upload your editor log to your FMOD Profile that would also help with my investigation.