Bypassing outside cblocks on VPN

I have both wireguard and OpenVPN setup on ipfire.

Very occasionally when I connect to other organisations’ WiFi, I won’t be able to use either VPN. I changed OpenVPN to use port 443 and that has helped most of the time when wireguard is blocked.

However, the other day, both were blocked.

What are other ways I can try to get around third party blockscof VPN?