Outlook.com - forwarding emails ... no Save button

My incident is still open with the support. Periodically get told investigation is ongoing.

Same issue occurs for me aswell.

This is ridiculous.

How to fix it or when you will fix it?

This is it!

I actually had to add a phone number to the 2 step verification part of my* account. I suggest whoever has this problem to try and add new methods of authentication. Outlook doesn't tell you why you can't add forwarding there but, at leat in my case, it had to do with adding a phone number to the Account Security section of my outlook (web).

I'm not 100% sure but I have a strong feeling it would have to do with the security info of your own outlook account in almost all cases since, according to what I have read in this forum it is not a cache problem.

Download Firefox. I cannot get the save button to show in Edge. Typical Microsoft, their own software never works properly.

I faced the same issue, I added my mobile number in the account info and Save & Discard button visible in Forawrding window.

It seems to be a reputation thing and to stop it being used as a Spam relay.
Adding a mobile improves the reputation and so very much less likely to be used for such malicious activity.