Label command not working when adding to an Issue

Summary

(Summarize the bug encountered concisely) /label~ command not working in the comment input field for an issue

Steps to reproduce

(How one can reproduce the issue - this is very important) Go to an Issue and run the /label~ command, it will try to add, but nothing happens, where you would usually get a response "command added/ran" you get no response.

Expected behavior

(What you should see instead)

Actual behavior

(What actually happens)

Relevant logs and/or screenshots

(Paste any relevant logs - please use code blocks (```) to format console output, logs, and code as it's very hard to read otherwise.)

Output of checks

Results of GitLab application Check

(For installations with omnibus-gitlab package run and paste the output of: sudo gitlab-rake gitlab:check SANITIZE=true)

(For installations from source run and paste the output of: sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)

(we will only investigate if the tests are passing)

Results of GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of: sudo gitlab-rake gitlab:env:info)

(For installations from source run and paste the output of: sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production)

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)