Over the past couple of days, more than once I have had a situation where I trade in a minion in Battlegrounds, and the graphic showing the number of gold updates but not the number beside it. It then uses the number to deny the purchase of another minion.
The situation today: I was playing A. F. Kay. I had picked up a Crowd Looter and Salty Favorite from my initial pool, and a Swabbie as a minion. I ran out of time before I could hit the level up button.
So, one the next turn I leveled up (costing 1 - down to 5 gold), grabbed a Rat Pack (down to 2 gold), traded in the Swabbie (should be up to 3 gold) but was denied due to the total reading 2 gold, despite the gold graphic showing the proper 3 gold.
I was using a Windows 10 machine
I have a screenshot if you want it, but it will not allow me to post a link to it here.