Local adjustments made with mask won't save

I am creating masks with the brush tool in ACR, and several times now, I have lost my mask edits.

At first I thought I accidentally hit "Cancel" instead of "Done." *This is 100% not the case.* 

I then considered the possibility that my mask edits simply weren't being saved correctly after clicking "Done." So, I decided to do some edits, save the file (clicking "Done"), reopen the file, make more edits, save the file again, rinse and repeat. I figured this would safeguard me from losing a whole bunch of edits in case of shoddy saving. This worked fine until it didn't.

Several times now, I've opened files only to discover that some masks--masks that were saved properly at some point (confirmed)--have been lost. Oddly, the mask is not lost in its entirety, but what appears is a much earlier version of the mask, both in terms of the coverage and sliders.

This is beyond maddening.

Tech specs: I am editing RAW files from a Nikon Z7ii in ACR (Photoshop v. 23.3.1) using a MacBook Pro (16 inch, 2021) running MacOS Monterey v. 12.2.1.