I continue to have this same issue, and have for quite sometime. I'm retired IT, so I know my way around PCs, but this one I do not have a clue except it's likely a combination of elements causing this problem: OEM (Dell) OS but not as likely but tiny possibility, NIC (Killer NIC firmware) and/or NIC network driver very very likely, perhaps running multiple OSes like XP, Vista, Windows 7,10, 11 and conflicting network driver software possible but not seriously likely, other hardware (all OEM) in my system (Dell) causing a conflict, the days of IRQs, DMA and other shared resources conflicting isn't likely but maybe a slight slight slight possibility. I've tried multiple adjustments (logging everything I've changed), turned off all PCs except Windows 10 and 11 boxes, reset router, switches, modem and isolated segments of my home network (all is Private and discoverable) and still does not work consistently. I say consistently because on a couple of rare occasions I all of a sudden see my Windows 10 PCs from Dell Windows 11 PC (Killer NIC). It seems every time it does just start working Dell does a firmware update and I assume it's fixed, but then lo and behold it gets broken again. I basically have given up because I've spent uncountable hours trying to isolate and determine the issue. I strongly suspect my Dell i9 with a Killer NIC the issue. Why? Because I have a HP Laptop upstairs running Windows 11 and it can see my Windows 10 PCs on the network along with all my other Windows versions with no inconsistency. This is why I gave up because the only real suspect in my case is the Dell i9 Killer NIC on my network. I've reported this but no solution that fixed it consistently. One of these days I may buy a Wifi NIC and try it in my Dell but first disabling the Killer NIC stuff.