This is a DB1 running stock firmware v5.2.4 build 230404. I picked up an Electronic Chime this weekend to try. I believe this is a discontinued product, but a Canada Computers had an open box unit for sale.
I went back and searched our Doorbell 101 and in our TROUBLESHOOTING TIPS: I found this:
⦁ If your Chime has suddenly stopped working (2020) - TechBill, TechBill - misally(If you suspect your Power Kit is the reason your Chime is not working, here is a Power Kit replacement thanks to hibby50 )