If you cannot see other computers on your network in Windows, then you need to enable network discovery and file sharing feature to see all the computers.

If Network Discovery is not working & Workgroup computers or Network places are missing or not showing in Windows 11/10, see this post.

I took the 5GHz connected computer, disconnected from the network, and reconnected to the 2.4GHz network. No dice, the two wireless computers still cannot see each other.