Hi,
Please check if the Windows 10 host has installed the April 21, 2020—KB4550969, as far as I know, it may address the issue that Num Lock and Caps Lock keys out of sync between client and host during Remote Apps connection.
https://support.microsoft.com/en-us/help/4550969/windows-10-update-kb4550969
If the reply could be of help, please help to accept it as an answer, thanks for your cooperation!
Thanks for your time!
Best Regards,
Anne