I would check that BIOS, drivers, and other firmware is up to date on the laptops.
We have been issuing Lenovo X1 Carbon Gen 9 laptops with Lenovo ThinkPad Thunderbolt 4 Docks and connecting to Dell P2222H monitors with DP cables.
We are having issues with getting at least one the monitors to be recognized, sometimes they do, sometimes they don't, it really varies with each set up from user to user.
Do you have any suggestions?