On Feb 15, 2023 I noticed the SmartThings App has mostly stopped working for Schlage Connect locks. I cannot remotely set via the App and cannot lock or unlock the does via the App. My app is version 1.7.94.21. I also tried reinstalling some of the prior SmartThings versions and none of these restored this missing functionality.
They’re working on an issue with locks, hopefully when they solve that your problems will resolve.
What are you using to set lock codes? Which hub do you have and what version is it running? Which Schlage lock, BE469, BE469ZP, ???
In general, the stock Edge driver for Schlage is buggy and doesn’t expose all the features of the lock. I suggest using the [ST EDGE] Z-Wave Lock PH - Devices & Integrations / Community Created Device Types - SmartThings Community driver from @philh30. In addition to fixing many of the bugs in the stock driver, it exposes more features of the lock. The beta version of the driver in the same channel provides a capability to see how/who unlocked the lock as well as making that available as a trigger in Routines.