That is much easier said than done considering it often ends up in the middle of the screen when I reach the bottom of the topic.
Generally speaking, on mobile you can tap anywhere on any website or any app and drag your finger up and down to scroll. This behavior sometimes doesn’t work in Discourse, preventing normal use of standard mobile browsing behavior.
For what it’s worth, I reported this because I’d never seen it before and so I thought it was a recent degradation. I just checked a few Discourse communities I know of, and it may not be as recent as I thought. The bug is reproducible on https://community.kitsun.io, which is on commit 186379adac from November 17th. However, the bug is not reproducible on https://community.bunpro.jp, which is on commit 763f48abc7 from September 3rd. So not as recent as I thought, but introduced sometime 2-4 months ago.
I’ll try to work around it, but hopefully that commit range makes it easier to investigate if you choose to.