I've used sendfirm.exe on Win 10 and it worked fine for me. Just make sure you run it as an admin and that all your drivers are up to date. Sometimes, compatibility issues can be fixed by running the program in compatibility mode for an earlier version of Windows.
In case you're still hunting for this info, I have a suggestion. I know a platform with a
cheap Windows 11 Pro key. Upgrading to Win 11 might also help with any issues you're having.