Annoying issue with LibreOffice Online (observed in it's incarnation as Collabora CODE from v 3.x up until the latest 4.0.4): If you select a whole sheet / table in CODE Calc and then change the font or cell formatting / alignment, the sheet starts to scroll down (or sometimes to the right) automatically with high speed. It can be interrupted by pressing page up/down, cursor and "home" keys all after another - not sure which of those keypresses actually breaks the manic scrolling. ;) You then have to scroll back up over many pages to get back to the actually used part of the sheet... From a usability perspective that's annoying to say the least. :)
Additinal info: Often it's actually "sufficient" to select a whole row or column and apply some change (like formatting) to it to trigger the runaway-scolling-effect. Pretty annoying... I'm mainly using Chromium (currently Version 73.0.3683.86 (Offizieller Build) Built on Ubuntu , running on neon 18.04 (64-Bit)), but IIRC we also observed this behaviour with Firefox users.
Ok, just got confirmation from a FireFox user, it also "happens always" (quote) in FireFox. (Not actually "always" from my observation, but pretty frequently, and apparently it doesn't matter if FireFox or Chrome is used.)
This has been fixed by the following commit in master. The fix will also be released in a Collabora Online/CODE update in the near future. https://cgit.freedesktop.org/libreoffice/online/commit/?id=6cc7bad2e035416044020cc9adc876a2d15d63db author Szymon Kłos <szymon.klos@collabora.com> 2019-04-04 18:36:21 +0200 committer Szymon Kłos <szymon.klos@collabora.com> 2019-04-05 10:59:21 +0200 Calc scrolling with selection fix