Win 11 - shared folder stopped working

[Mcinwwl]

So, Hello after a while, and I need help.

I have the DESKTOP and the LAPTOP. a year ago or so I fought hard to enable shared folder on LAPTOP to be seen from DESKTOP. I did all the registry tweaks described here: https://www.wintips.org/fix-windows-11-24h2-cannot-access-network-shares-0x80070035/ , checked all the necessary services are running, set network as trusted on both computers, enabled connection without password, turned on network discovery. Well, it worked.

Then I left it off for a few month and, after a windows update and changing home router,  blam, I cannot access shared folder on LAPTOP anymore. Windows cannot access LAPTOP. error 0x80070035, The network path was not found.

After a few hours of trying to set it up again, I gave up. And id the opposite, namely created shared folder on DESKTOP and accessed it from LAPTOP. well, it worked. Which is a workaround, and "maybe" proofs that new router is not an issue, as devices are shown in network panel on both machines. But the whole situation makes me crazy, and I'd love my machines to work as previously.

Do you have any slightest hints what might have just happened? and how to fix it? needless to say top google search is about an issue nearly 1:1 as mine, and with no answer :/ https://www.elevenforum.com/t/cannot-access-shared-folder-via-network.37320/