I have had the same issue for years - initially my Win 8.1 machine (2015) (pc #1) would talk to my old Win7 machine on the wifi network. Win97 was replaced with a 2016 Win10 machine ( pc #2), and win8.1 happy talked to Win10. But when #1 was upgraded to Win 10 (i.e both Win10), pc #1 and #2 would never talk to each other despite all being set up equally. When #1 died a few weeks ago and was replaced with pc #3, a Win11 machine, despite both being set up equally and on the same network (I have followed all the steps listed in this thread, which are the same steps as being posted in all the other forums), the ONLY way they now talk is if I turn the pcs on, AND THEN reboot the wifi router. It's not perfect, but it's a workaround solution.
In my opinion the windows networking capability is getting worse with each release.