Turning off email notifications for individual issues

I have commented in a number of issues on GitLab.com and I'm now getting an email every time every time anybody comments on any of them. This is useful when they come from projects I'm actively involved in, so I don't want to turn all email notifications off. But I do want to be able to quickly and easily unsub from issues discussions that no longer interest me.

I do not allow email to display HTML (for security reasons) and the plaintext version of these emails do not seem to contain clearly labeled a link for unsubscribing from the notifications. It would be a significant improvement to the UX of GitLab if the plaintext version of every email notification the site sends out, included not only a unsub link for that thing (the issue or whatever it is), but also an unsub link for the entire project. That way, if someone loses interest in an issue or a project, they can opt out of all emails relating to it without leaving their email client, or allowing it to display HTML.

The second issue I struck was When I visited the page for the issue to try to unsub, I couldn't see a button or any other control for turning notifications off for that issue. I finally got it to display by zooming out my browser to 50% of its normal size. So something appears to be wrong with the way these issue pages are scaling or scrolling in my browser.

I use ABrowser (a rebranding of Firefox) on Trisquel GNU/Linux 8.0. I have uBlock Origin and NoScript extensions, but both of these have been turned off for GitLab.com.