Back in 7.12 or something that I was using before, I had the Editbox Lines set to Automatic. If I typed something that pushed the Editbox out to more than one line, and if I deleted all (or most) of that entry (e.g., Ctrl-A then Del), I could still scroll through the Editbox with just up/down-arrow.
I just updated to 7.32, and that no longer works. I can scroll up with just up-arrow until I hit a multi-line entry, but then I MUST use ctrl-up-arrow to get past it.
Deleting all (or most) of that entry - which actually puts the Editbox back to a single line - no longer works, in the sense of allowing plain up-arrow to scroll past what is now a one-line entry.
Given the previous bug/fix of 7.31, this may not be considered so much a "bug" but it is a change of behavior, and I suspect it's a side-effect "bug" of the fix in 7.31 for evidently not saving Editbox lines at all.
And for the sake of consistency, a single-line Editbox entry, even if it wasn't that way to start with, should allow for up-arrow to scroll past it.
Something I just checked: If I've been working on - i.e., editing in the Editbox - a message that has not yet been sent, if I type more than one line I can't use just up-arrow. But if I delete part of what I've been typing so it goes back to 1 line, IN THAT CASE plain up-arrow does work again.
It should behave the same if I go back to a previously-entered message and delete enough of it that the Editbox goes back to a single line.