It’s probably a problem with the UEFI, the windows info got overwritten, and you can probably fix this with efibootmgr

It happened to me too, but unfortunately it was some years ago and I’m not at home to find the related notes that I took. I remember there was a windows utility to rewrite the boot loader. But probably in your case the boot partition is still okay, just the UEFI entry got overwritten and you just have to add it back manually.

Check the troubleshooting section of the wiki page to have a tip on the windows booting location

Finally, a relatable story that warms my heart in these trying times!