as a basic first step to getting the full functionality of specific row expand/collapse, we are trying a "collapse all" button in one of our apps.
we have three tables nested inside eachother and the outer-most table is happy, but the table inside of it complains about no such function table1.collapseRows()
is it because of the nesting? both tables have row expansion option selected in the table component inspector > Content > Advanced Settings > "Enable expandable rows"
ah nevermind! i made a screen recording and it started working just to spite me lol. i refreshed the app editor a bunch of times and toggled expandable rows option on and off before writing this, but something must have shaken things loose (in a good way!)
my colleague and i both have like 2-4 instances of our profile icons editing the app in Multiplayer due to multiple tabs open, I wonder if that may have something to do with it 
glad it started working, but that sounds frustrating. Have you come across anything similar lately? I haven't found any known issues with this (even with multiplayer)