@SteveITS
I contacted support and they said I could only downgrade to 24.03 via the installer.
I went back to 24.03 and it fixed my DHCP and SQUID problems. Turns out my VLAN issue was due to a new feature added in 24.03 and I've attached the excerpt for anyone else experiencing the same issues with VLAN giving firewall problems
I couldn't connect to my VLANs with the following appearing in my logs
VLAN123 Default deny rule IPv4 (1000000103)
I could ping devices but that's all.
"Beginning with pfSense Plus software version
24.03 and pfSense CE software version 2.8.0,
the default configuration is explicitly
set to an Interface-bound policy to
enhance security. It appears that in
your previous version, the default
was configured as a Floating state type.
You can read more details about this change here:
https://www.netgate.com/blog/state-policy-default-change"
Changing the Firewall State Policy to Floating States (System>Advanced>Firewall & NAT - Advanced Options) solved the VLAN problems for me.