Issue edit window is unscrollable after application of template

Summary

After applying a template the issue edit window is no longer scrollable.

Steps to reproduce

  1. Create an issue or edit an existing issue
  2. Apply a template
  3. Try and scroll within the "Write" window

Example Project

Any project will show this behavior.

What is the current bug behavior?

When a template is applied the "Write" window is no longer scrollable.

What is the expected correct behavior?

After applying the template, I should be able to click in the "Write" box and scroll within that (focus).!

Relevant logs and/or screenshots

Screen_Recording_2020-10-20_at_11.17.43_PM

Output of checks

This bug happens on Gitlab.com

Results of GitLab environment info

Expand for output related to 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`)

Results of GitLab application Check

Expand for output related to the 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)

Possible fixes