This forum sometimes does not like a VPN

[Pecoflyer]

Hi, for safety reasons I use a VPN to connect to the Internet.
When connecting to the forum, sometimes it opens flawlessly with VPN on, sometimes it refuses to open. If I disconnect the VPN, the problem is solved.
The way the VPN is configured on my PC prevents double tunneling of websites. Is there a solution to this annoying problem ? ( when VPN is disconnected, my privacy is gone...)