BE88U prevent connection to Multiplicity KVM

[Lilrex]

I am using multiplicity KVM from Stardock software. I tried to replace my Asus AX88U non-pro model router with the Asus BE88U router and the KVM wont connect with the BE88U but will work with the AX88U.

I also checked the firewall on the target machine and the software is in the list, the app is set to secondary, and KVM is not disabled.

Other things I have tried so far:

Factory Resetting the router

Removing the switch and connection both PCs directly to the router

Enabling the DMZ and testing both IP addresses

Port forwaring the Multiplicity documented ports

Double checked all firewall settings in Windows Defender Firewall to make sure no specific settings were enabled for the primary PC to connect

Completely disabling the firewall on the router

[jzchen]

UPnP is disabled on the latest firmware for (most if not all) ASUS routers.  Do you need to reenable it, (or did you already try reenabling it)?

[Lilrex]

where do i find that option?

[Lilrex]

I turned on UPnP in the WAN section but still not finding the software

[Lilrex]

Ok so I checked the firewall settings and did see public was not enabled so i did convert both PCs to a private network and the KVM works. But I am so confused as to why with these settings unchanged i plug in the AX88u and everything works perfectly and the BE88U it breaks with 0 changes