This is something that has big pottential for abuse. Owner of the card can’t do anything if the user cancelled the rental, so the user who cancelled the card can snipe it back from the market. Ulimatelly it could be never ending contract if the owner can’t cancel it before the card is already rented and cancelled.
Yes this is a known bug by splinterlands. PeakMonsters had to change their UI to avoid this bug.
also this is similar to ticket 93