My one remaining On/Off Button still on a Zigbee 5.2.1 hub also holds its charge (firmware 2.2.010 as many of my buttons are). Except when it doesn’t. It was OK for a couple of weeks, lost its charge overnight, and has been OK since.
My one Shortcut Button is also still OK but eccentric with battery reporting. It loves 87% but then dropped to 16% and back up to 87%, had a brief period on 60-something and is now at 47%. So it shows signs of poor battery life but not the bonkers battery bug. That seems to be the sort of thing that some users reported several months ago.
There still seems to be a secondary issue with battery reporting even on Zigbee 2.9.0. The batteries sometimes show at 0%. Power cycling Tradfri outlets used as repeaters seems to help with that. If I had an Ikea gateway I’d probably be addressing the firmware on those.
I’m wondering what will happen if there is a firmware update required on the IKEA buttons. Will ST distribute the updates?