HP ProBook 6550b hangs on kernels above 14.0-RELEASE

Hello,

====
One of my old laptops (HP ProBook 6550b) was running FreeBSD 
14.0-RELEASE (amd64) perfectly fine, but upgrading to anything higher 
results in a boot that hangs at the line:
psm0: model Synaptics Touchpad, device ID 0

A while ago I tried upgrading to 14.1-RELEASE and run into this problem. 
Back then I decided to wait, hoping this glitch would be ironed out in a 
later release. But today experimenting with 14.3-RELEASE and 15.0-STABLE 
from 20251113 I got the same results.

It would be great to find a fix for this and would like to help 
troubleshooting this issue. I'm not even close to a kernel developer 
though, but perfectly capable of gathering all kinds of information (I'm 
a FreeBSD-user since version 4.4) and help testing.
====

This is what I posted on the FreeBSD forum. The post is here:
https://forums.freebsd.org/threads/hp-probook-6550b-not-booting-14-3-release-15-0-stable.100065/

The conclusion there was to try again on this mailing list.

I tried kernels 14.1-RELEASE, 14.3-RELEASE, 15.0-STABLE and the most 
recent version I tested with is 
FreeBSD-16.0-CURRENT-amd64-20251110-dbb34d496708-281771
The problem is still there. It seems the system locks up since scolling 
back up doesn't work either.

I wonder if anyone is willing to look into this. The offer to help 
troubleshooting this and test a solution (if any) stands.

Kind regards,
Michael