When the number of tokens in your inventory drops to 1 the 1/10/100 selector gets hidden but doesn't reset meaning you can't trade the last one until you dig up a 2nd or reload the game. Only relevant if you had exactly 11 or 101 before the trade.
#Palaeontologist trader quantity selector hidden without reset
stiff grove
upper sparrow
Can confirm, just ran into the same issue and went here to post about it
