ESP Connection Refused Question

[Benjamin Cardon]

Hi, my company has a GlobalProtect VPN and I've been successfully
using it using GPopen and openconnect for years. A few months ago,
they changed something in our network or VPN that is causing the VPN
to fail to connect via ESP when I'm in our office, though it works
perfectly fine outside the office network. I have tried to figure out
what exactly is preventing ESP from starting up and the only thing I
can really see in the logs that is different between in the office
versus out of the office is this log

Jul 30 11:06:33 xps15 plasmashell[3116179]: 2024-07-30 11:06:33.467
INFO  [3116179] [GPClient::onVPNLogAvailable at 518] ESP receive error:
Connection refused

My question is, what does this log line imply and where is the
connection being refused from? Is it just UDP packets to the gateway
address? Prior to this, it does do a handshake using Okta to sign in
which works just fine so it's transferring the ESP packets explicitly
that seems to be the problem. To me, this suggests a network
configuration/firewall issue but I need more info to tell our
networking team what to investigate.

Any help would be appreciated.

Thanks!
Ben