Are you accessing these shares by IP, or by name (WINS)? Edit: I can’t read.
What does your netmask look like? 255.255.255.0, or…?
Other forehead-smackers I would check:
Ensure both machines are in the correct time zone and have their clocks set correctly. Windows authentication will silently and mysteriously fail if either computer’s time is off too much, IIRC around 4 hours.
Ensure both machines are updated to the same Windows build. Some dissimilar builds of Win10/11 are incompatible with each others’ network shares for no readily identifiable reason. I’ve run into that one before.