Can the following article help you? Article - "How to access Flexnet based PTC products via VPN": https://www.ptc.com/en/support/article/CS119513
Creo launching issue with VPN
please provide more details. Does this mean that Creo is working when VPN is off ?
I guess your problem has been solved by now.
But I would be interested to know which operating system you were using? Windows 10 or Windows 11?