I had this happen the other day, I just kept playing, and avoided pressing sell. Pretty sure it’s a bug, not intended for mobile.
I noticed this since the last patch on mobile. Accidentally sold a few jokers, hope it’s fixed soon.
Just deselect the card. Alternatively, click the sell button to sell it.
How do I deselect it? I’ve tapped other cards, long pressed other cards moved them around, nothing.
It’s a known bug on mobile. You need to return to the main menu, then you can continue your run.
You can’t really deselect it on mobile since you’re not supposed to be able to select them like this in the first place, afaik.
You may have to click the card in question, depending on your mods you can sometimes do stuff against multiple jokers (like attach jokers to other multi-sided jokers)
Android
Tap
Long press
No click on mobile.
it’s a but that can sometimes happen. I think closing and reopening the game fixes it