We rent out of our apartment as well and had numerous problems with keys before too, so we no longer use them. We got this new lock a couple months back and absolutely LOVE it! It syncs directly to my AirBNB calendar, sends guests emails with key code and instructions as soon as they book a stay, disables codes at time of check out (and accurately lol), and auto updates itself for me. I don't have to do a thing or have to worry about keys or anything myself, it's awesome.
Here's a link to check it out, I highly recommend it!
https://www.amazon.com/AirLocking-Smart-Lock-for-AirBNB/dp/B0759NPC5Y/ref=as_sl_pc_tf_til?tag=airloc...