Problem with "mailto"

First of all, this is new. It didn't happen a year ago.

I have several forms that use the Submit button. Some use the built in Submit function, others the invoke a javascript that uses "mailto:". They work beautifully if the user uses Outlook as the default mail, but anything else doesn't work. It just sits there. My instinct is that this is a configuration problem, most likely a Windows 11 problem, but I don't know what to do to fix it. Needless to say this is a serious problem.

Any suggestions would be greatly appreciated.