Tagging people has issues with spaces

• Repro 1:

Tag a Person using the @

After writing the @ press space

Result 

The Editor (full or quick mode) will write another at sign like this @@

Repro 2:

This also happens if you write characters after the at sign and press space to enter a second part of a name, most likely, a surname.

If you repro this you will notice more issues like trying to delete the second at sign will not cause the first one to be able to search for a name as it is now an usual ASCII char not having the special functionality anymore. And some glitches while deletion using the backspace key.

If you delete the second at and again press a space key after the first at sign it won't repeat. 

Expected behaviour:

Writing an @ and space should not cause a second @@ 

Instead the first should remain fully functional to tag people.

If anything is unclear please let me know. 

I can reproduce this issue anytime. Especially on Edge / Android, while I am sure that this is no Browser issue but rather a techcommunity.microsoft.com behaviour.

So it belongs here to be triaged and hopefully fixed. 

Sidenote about tagging and etiquette

https://techcommunity.microsoft.com/t5/community-faqs/tagging-users-etiquette/ta-p/1820261

P. S. Please add the tag Editor to give the change to report others for Editor related issues, too. Current Tags don't seem to fit.