GS110TP V1/V2/V3 - This GS110TPV3 is not registred for the current user, please login with the regis

Wild guess - there might have been some short-lived firmware enforcing the registration for a short time. This applied just to one of the three hardware versions, not all three however. Can you block the IP addresses of the switches in question from accessing the Internet? Not sure if a reboot is required. From that point, you should be able to login with the local admin password again. After applying the current firmware, you might have to go over the online registration again (allow Internet access for the switch IP again) or register it manually using the key -> How do I find my NETGEAR registration key?