Squid does ignore firewall (routing)rules

[dr0n3]

Hi,

I've got two outgoing interfaces on pfSense. The usual WAN and a OpenVPN connection.
I use squid mostly to block ads and use the VPN to bypass restricted YouTube videos (I'm from Germany and there is a thing called GEMA that no one likes).

There is a firewall rule on the LAN interface, which takes everything and routes it through the VPN interface.

Sometimes, the VPN get's a RTT of 300ms and more, which makes me change this rule to route traffic through the normal LAN interface, because everything is awefully slow.

If I do a tracert, the VPN isn't used anymore and everything is great.
The browser however still connects through the VPN and whoer.net tells me, I'm still located in Switzerland.
If I turn off the proxy in Firefox, everything is back to normal. If I turn it back on, I'm in Switzerland again.

How do I tell squid to recheck, where traffic should go?

Reseting the state table and restarting squid/pfSense doesn't do the trick.

Edit: I'm using squid 3.1.20 pkg 2.1.1