Issue with using userName_number that has underscore

Please check if you can mention a user that have underscore in the UserName since I see the issue again

EDIT: this jssue can be replicated only in comments/replies but not in a new posts here - please verify

Example: test it out here with a new post if it works and test the same scenario with comments and/or replies

Linda Poulsen_1 user name is linda__1 and when user in the mention the the 1 part id not being formatted forrectly and other Linda user is being called (userName without the_ _1 text).

Note: probably that is why the Dev team were using comma sign after the user name to detect there the UserName ends but if the comma was removed because of our request the issue came back again.

EDIT: see a comment below