Problem with large transfers after update

[hhjohan]

I have a strange issue that started when I updated my Pfsense firewall.
I have my servers behind the firewall in DMZ with both web and mail hosting.
After the update when I from internet transfer a webpage it is extreeamly slow and only the text shows up, not images. Email is only partly working, its like everything that's more then just some kilobytes got stuck.
Traffic from LAN to WAN seams to be working as it should.

I have my servers set up on a DMZ with the public ip-addresses that I publish on the WAN interface, don't know if that's what causing the problem here.

I have tested multiple newer versions of Pfsense with no luck. Seams like something have changed from one version to another.
The version I tested last that wasn't working is 2.4.4 patch 3 (64-bit).
The version I am running now that is working is: 2.2.5

I have also tested different hardware but that doesn't change anything.

Have anyone been dealing with a similar issue or have any idea how I can troubleshoot this?

[Harvy66]

Possibly asymmetric routing?

[hhjohan]

@Harvy66 Yes, that absolutely an interesting idea that I will look up.