Windows 10 laptop cannot connect with Linux Samba server (SMBv3)

Question

I've set up a Samba share on a Ubuntu 20.04 server using SMBv3, disabling SMBv1. Several Windows 10 laptops can connect to this server, but one refuses, and I don't see anything in the Samba logs with loglevel increased (it should at least show a connection attempt and a specific file for this laptop - neither is there).

• It seems like the problem is on the laptop side; I've looked at the logs, but am not 100% what to look for - it seems like the Workstation service should be running, and I can't start it; Netlogon and Remote Desktop Configuration services can't be started either (these services seem dependent on each other - workstation depends on Netlogon and Remote Desktop Configuration and both depend on Workstation).
  How can I start any of them?

I've tried:

• changing ownership of several registry keys to SYSTEM and Administrators, but after changing this and restarting, other keys came up; is this an endless road?
  CLSID: {C2F03A33-21F5-47FA-B4BB-156362A2F239}
  APPID: {316CDED5-E4AE-4B15-9113-7055D84DCC97}
• running Windows system repair (keeping files), but that didn't do anything and the whole repair was over in 1s
• running, with no change afterward: sfc /scannow

  Windows Resource Protection found corrupt files and successfully repaired them.
  For online repairs, details are included in the CBS log file located at %WinDir%\Logs\CBS\CBS.log
  

Should I reinstall this system?