Hello:
@ffuentes, You stated "My squid issue comes from before and I think is a config issue in my case...", a squid config issue or a pfSense config issue? Fist and foremost any kind of config issue would drive me insane! I would hunt it down and fix whatever was wrong. If that meant starting fresh until it worked (correctly) then that's what I would do (and have done in the past). Total PITA, but, I then know I don't have to play that "well maybe because I did/didn't do something and now that might be what's causing this new problem." SO FRUSTRATING!!!! Problem with this approach is obviously time (and money).
Either way, you might want to consider fixing the issue so as to avoid a future headache. I'm guessing this unit is a unit in production so fixing may require doing it when the impact is at a minimal. Always hated that, but no greater joy than knowing the config is perfect and possible future headaches will be avoided (well at least that's how I felt).
As stated previously, I don't use squid (not that I haven't experimented with it in the past and decided it wasn't necessary for my needs). My setup is very vanilla with a dash of a few VLANs thrown in. My conversion to 2.4.5 was easy peasy! No problems, less than 5 minutes total. But then again, I'm not utilizing pfSense to it's full potential.
I just hope whatever issue(s) it is, it's found quickly and COMPLETELY resolves the problem for everyone. Feel so sorry for anyone going through this as pfSense is an awesome product!