Synology NAS no file shares from Win11

You can see the error log at
Main menu, Log Center
click logs on the left and connection logs in the top right

Fix here Involves setting the Win11 pc to send NTLMv2 instead of a combination of LM and NTLMv1 which both have security issues.

If the laptop is part of a domain, Your administrator may have to add a Group Policy to make this stay fixed. Probably a good idea anyway.