Reported by archon1410 on Discord

Steps to replicate the issue (include links if applicable):

• Visit the mobile website (skin=MinervaNeue)
• Log in
• Turn off DiscussionTools via Special:Preferences -> Beta features -> Discussion tools -> Off
• Turn off DiscussionTools' features via Special:Preferences -> Editing -> unticking everything at the bottom
• Visit any talk page on the mobile website, such as https://en.m.wikipedia.org/wiki/Talk:Tomioka_Tessai

What happens?:

• "Add topic" button is visible

What should have happened instead?:

• "Add topic" button is hidden

Software version (skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):

• Probably related to T328942