How many miles? Those issues are all related to serial data messages coming from the DDM, and the honk might be a security-related confirmation that the DDM just sent a "lock door" message. You might try configuring Driver 1 and 2 to NOT use the horn as the fob lock confirmation, if they are using it now.
The issue could also be just the switch in the door latch assembly that tells the DDM that it's locked. That would explain the display and the lights, but maybe not the honk.
The DDM may be getting flaky with age or water contamination, or it might be flaky, intermittent wires in the middle of good-looking insulation. The driver's door gets the most flexing of this harness hear the hinges. You might pull the boot back and look at and flex the wires to see if any feel funny.
The issue could also be just the switch in the door latch assembly that tells the DDM that it's locked. That would explain the display and the lights, but maybe not the honk.
The DDM may be getting flaky with age or water contamination, or it might be flaky, intermittent wires in the middle of good-looking insulation. The driver's door gets the most flexing of this harness hear the hinges. You might pull the boot back and look at and flex the wires to see if any feel funny.