Bummer…but starting fresh once in a while can be very helpful.
I’m running ethayer’s Lock Manager (the “beta” version) and it’s been faultless w/my Schlage Connect 469. Managing codes from the SmartThings app, set up lock after 10min CoRE piston, lock codes that only work during certain days/times, lock during alarm enable, etc., and haven’t run into any issues. (Probably just due to my clean living and love of small furry animals.) 
On the other hand, I was recently adding an Iris keypad to my security setup and found myself down a rat hole of Smartapps and settings that left things completely screwed up at one point. Decided to take the same path as you - removed and reinstalled everything last night and now it’s working perfectly. Tah-dah!
Hope your reset goes well…my Schlage Connect lock (and related automations) is one of my favorite parts of my SmartThings automations - not having to worry about always leaving the front door unlocked when away or at night (which we used to do constantly) is really nice. Also love the ability to press the Schlage button on the lock to lock it from the outside so that I don’t have to have a key w/me when walking the dogs, or family is leaving and kids have to go back to get something.
It says “beta” below, but it’s really a fully functioning, feature rich, and reliable solution.