Yes and no. Sometimes VPNs get blocked, other times they work. I routinely use NordVPN. I'm connected to PPRuNe at the moment via that VPN. Most of the time PPRuNe works OK. Every now and again it gets blocked (as do some other sites). Changing to a different VPN node almost always fixes it.
I think that what happens is that scammers start using a particular VPN node and when that high volume of activity gets linked to the IP address range of that node that IP address range gets blocked, as a crude countermeasure. No idea if this is the reason for your issue, but it may be. Try changing nodes, if you can, and see if that works