As you can see in the screenshot, I typed this and it's being hidden by the keyboard. Version 2.49.1 on Android; Gboard version 18.2.4.969776716-release-arm64-v8a at time of testing.

Huh, it's true.

You can swipe up to move the text box but you'd have to do that for every line.

Huh, I just tested it, [it works correctly] with 2.48.5. But with 2.49.1 it's indeed not automatically scrolling as I hit ⏎. However, it automatically scrolls as soon as I start typing, no it's not really an serious issue. [tested when writing a comment]

I would describe it as a "serious" issue that affects usability. It means that for every line break that ends up "underneath" the keyboard, I need to scroll to see what I'm typing and then open the keyboard again.

I don't think the behaviour was like this before.

I'll note that the comment on replying to behaves properly -- it gets scrolled down correctly.