BIOS firmware version 1.15.3 was a stable one that worked for me:  [URL]  
Hi Dell, The Dell Precision 7730 BIOS update 1.16.1 as at 30/07/21 has issues. Namely, when docked and after undocking, the laptop's screen freezes or blacksout. That is, the laptop only works when connected to the dock and externl monitor. Dock is WD19TB.  I have attempted all means of troubleshooting and updating every single driver but it does not work. I had to revert to the 1.15.3 BIOS version which was stable and fixed the problem.  Could the technicians please look at fixing this with their next BIOS firmware update? Thanks, Ed
Dell Precision 7730 BIOS Issues