Warpinator on Mint 20.1 not partially working
 

I have three systems on my home network, all running Mint 20.1 and Warpinator.

Two computers work fine, the third displays a 'No Entry' traffic sign indicating one-way connection only. It cannot see the other two. All run the same kernel version, have the same workgroup name, same port and can ping each other. Angry IP Scanner shows everything as expected. I have rebooted, turned off the firewalls etc. - all the obvious things.

So to make things clear: three computers, two can see three computers (but not connect to one of them), the third cannot see any at all.

Any ideas as to where I should look next?

Edit: just realised that the third machine accesses the network via a wireless access point. So that's obviously the 'missing link'. I will investigate further.

Sounds like misconfigured network, are they all on the same subnet?

Yeah, that was it. Main network on 192.168.1.xxx, the access point was on 192.168.0.50. Solved!