Win11 is partially blind to Win10

If it were me I would try creating credentials.
All kinds of networking issues are a result of Microsoft tightening security for Windows 11 24h2 and above. Credentials solve most of these issues.

Create a Windows credential for an account & password on all computers on your network you are sharing files/printers between. It must be a password, not a pin. While you can still use a pin to logon to a device, you must restart the device and log into it using a password at least once for this to work.
Even if you are using the same MS account on multiple machines, a credential should be created to the other.

In other words, Each computer should have a credential for each of the other computers it is sharing files or printers to/from.


To create a credential:
Go to Control Panel>Credentials> Windows Credentials>add a windows credential

In the "Internet or network address" box, type the name of the computer on the network that you want to access.
In the User name and Password boxes, type the user name and password that you use for that computer, and then click OK.
Note: It must be a password, not a pin.
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If using BLANK passwords

allow blank password use on the machine that is hosting the shares.
Open RegEdit and go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa. Set the LimitBlankPasswordUse value to 0. Restart Windows.