Connection failure

Hello

Recently purchased MP/KM then upgraded to MP KVM. Error message :" Unable to connect to given ip address ". I used given computer name for 2nd MP/comp but main comp doesn't see it and says use IP address of 2nd comp. Neither will connect. Here are some things I've done...

Both comps are Win 10. Checked the Win 10 windows firewall

,"allow Apps" tab says both comps checked, set to "Private"  neither are blocked. I have a VPN on main comp-disabled it. Rebooted Orbi router. I checked the port numbers under outbound/inbound rules in Win Firewall. There's a big list, unsure which line to check , port numbers etc ? There several with the same port numbers etc I pinged the main comp using the 2nd comp.

Main comp  under "About" tab says Version 3.55 Build 00101. KVM . Secondary says Version 3.55 Build 00101. Don't both have to be same version ? If so, how to install both of the same version ?

How do you check step by step for settings of "private/public ? Is this part of Home Group " ?

Thank you in advance