Okay, had to phone a friend for the PlayStation equivalent of alt since I only have base game on mine and all my packs are on the computer. 🙃
If you hit L2, you will cycle through placement options. Default is full tile, next is half tile, second press is free placement.
Counters can be stubborn about slotting, so you might choose to move the counter, then free place the item off of the counter where you want it, then move the counter back underneath.
Are you doing all that, and then somehow the counter is going to inventory on that last step? Make sure you’re not hitting the square button while holding it. We’re not sure what else would cause that. Does it show red like it can’t be placed, or does it look like it should be okay but then disappears anyway?