Was hoping the recent patch and event patch would fix or address this, but perhaps it hasn't been shared.
This happens occasionally with non-dungeons but every time with dungeons. The timers, placements, in progress, etc all just freeze. I have to click on a different tab (I use Army) and then back to the battle tab to force a refresh. Then I can see battles have ended to collect chests or if new placements have begun.
There's no way to properly show this in a screenshot collection, or even a video, so apologies on not being able to help with proper evidence.
This hurts while multi-tasking and doing dungeons cause I think it's battle time when in actuality I've missed 1 or more battles but don't know it. 