Can't access pc from another pc on the network

Vostro desktop 3710, Windows 11. When I try to access this pc from other computers on the network, with sharing on, I get, "Windows cannot access Vostro. You do not have permission to access Vostro. Contact your network administrator to request permission." I am the network administrator.

With sharing off, I get, "Windows cannot communicate with the device. It is available but not responding to connection attempts. A firewall or network security policy might be blocking the connection on port 'file and print sharing resource.'

The Vostro can connect to the other computers on the network, and the other computers can all connect to each other, but none of them can connect to the Vostro.

Everything is set to share by everyone, password off. Turning firewall off makes no difference.

Have spent hours online with Microsoft techs, who have remotely controlled pc and none of them could figure it out. Have reinstalled Windows and it didn't help.