System hangs in boot logo for minutes

[Notsignal]

HP Prodesk 400 G3 Mini: The system hangs for minutes (sometimes more than 4 minutes!) in the bios (HP logo) at startup.
After that, the PC runs "normally", feel and benchmark test show normal speed, test programs no errors.

Also a reboot from Windows takes about 4 minutes BIOS logo and then Windows starts.
What I have done to troubleshoot:
BIOS: factory settings / default settings, BIOS update
Hard disk (SSD) changed, Windows reinstalled

Any idea, what might go wrong or what I can do?

[TheOldMan]

If the system runs normal after completing the startup, then most likely Windows is waiting for an answer from something that is connected to the PC.  Disconnect everything except the monitor, keyboard, and mouse. If this something that just started to happen, then try using previous items that were replaced with different items.

If the keyboard is not the original and is USB, try plugging into the USB 2.0 ports instead of the USB 3.0, or until the logon screen to connect it, assuming that is the hangup.

Some systems cannot use the USB 3.0 ports until Windows loads.

[Notsignal]

Hello and thank you for your helpfull answer.

Actually I know this problem and actually I had already tested it, also between VGA and DisplayPort, some USB ports, different mice and keyboards. But your tip made me test it on another workplace. Here I have a KVM switch - and it must have given this HP no (?) or wrong (?) data about the monitor.

All other PCs have no problem there, not even HP PCs, not even other HP Prodesk 400 Gx Mini (or not Mini).

Thanks again very much, for your very helpfull hint.