Error trying to connect monitor

Dear @jber4282,
I have flashed DRIVE OS 5.2.6 on target again and at first I see no GUI on the display.

I see errors related to avahi in the end like you. Please check the log at install_GUI.txt (485.5 KB). Also,I see below messages on serial console similar to you whenever I turn on display using power button on monitor.

fmon_update_config: FMON_NVDISPLAYHUB: detected fault 0x4000
verify_rate_range: FMON_NVDISPLAYHUB: rate 2781250 below min 18750000

But I could get the display . I increased brightness of the screen for on safe side.

nvidia@tegra-ubuntu:~$  systemctl status display-manager
● gdm.service - GNOME Display Manager
   Loaded: loaded (/lib/systemd/system/gdm.service; static; vendor preset: enabled)
   Active: active (running) since Tue 2021-09-21 03:51:33 -05; 17min ago
  Process: 1109 ExecStartPre=/usr/share/gdm/generate-config (code=exited, status=0/SUCCESS)
 Main PID: 1126 (gdm3)
    Tasks: 3 (limit: 4915)
   CGroup: /system.slice/gdm.service
           └─1126 /usr/sbin/gdm3

Sep 21 03:51:33 tegra-ubuntu systemd[1]: Starting GNOME Display Manager...
Sep 21 03:51:33 tegra-ubuntu systemd[1]: Started GNOME Display Manager.
Sep 21 03:51:33 tegra-ubuntu gdm-autologin][1162]: gkr-pam: no password is available for user
Sep 21 03:51:34 tegra-ubuntu gdm-autologin][1162]: pam_unix(gdm-autologin:session): session opened for user nvidia by (uid=0)

Do you see the same issue with both Tegras? I had checked flashing only Tegra B as it has DRIVE OS 5.2.0 earlier.