Microsoft Store TLS handshake fatal alert: protocol version(70).

I'm facing the same issue (since a short time) , what worked is adding the following to the web exceptios:

^([A-Za-z0-9.-]*\.)?microsoft\.com/

or to enable the built in rule:

the built in rule is already activated 

Try adding: ^([A-Za-z0-9.-]*\.)?s-microsoft\.com\.?

Still no access

So these are my MS exceptions. I don't have the second one open permanently because of the MS Telemetry. When i enable the second rule it works for me...

So these are my MS exceptions. I don't have the second one open permanently because of the MS Telemetry. When i enable the second rule it works for me...