I don't have any connect/disconnect issues, and all lock/unlock activities show up in the "Yale Access" app logg so I don't think I have any problems with WiFi or Bluetooth.
My signal strengths are (according to the Yale Access app):
WiFi SNR: 46 (good)
WiFi RSSI: -54 (good)
Bluetooth RSSI: -75 (ok)
I have done some more testing and the issue I seem to have with my Yale Doorman L3 lock when the connection to IFTTT and/or Hubitat doesn't work is the following:
When I lock my door with the lock "button" on the outside keypad of the lock, nothing seems to be reported to IFTTT since the IFTTT applets doesn't run.
This seems to cause some issues for me with the rule in Hubitat in the next step when I unlock my door.
Since the virtual lock in Hubitat is already unlocked, the virtual lock doesn't change and the rule doesn't run when I unlock my lock.
That might be possible to change somehow though.
All other locking/unlocking (app, code, tag+code and manual knob on the inside of the door) works fine.
