Filter button for minions not visible after minion upgrade

Platform, device and operation system
Android, Samsung Galazy M10

What were you expecting to happen, and what actually happened
Tavern/minions: the filter button and number of minions dissappear after upgrading a minion.
If one tap on the postion where the filter button should be it reacts and opens. But after selection it iscstill diappeared

How often does this happen? When did it begin happening?
*Happens since update to 1.01 every time.

Steps to make it happen again
Upgrade a minion