Gui Logon Issue

[Bridger]

Current Setup:-
2 PC's (A and B) both running Win 7 and Internet Explorer 11 connected via bridged ports to pfsense box (X) running 2.4.5.

Issue:-
If I try to connect to the gui from A it hangs and eventually times out and I get error message "resource (192.168.2.53) is online but not responding to connection attempts". The connection to the internet works fine.

Logon from B works fine
Logon from A using Chrome works fine
Logon from A using IE11 to a similar box Y works fine
Logon from A using IE11 to a non bridged port on a different subnet does not work
Ping from A to X works fine

I have tried rolling back the registry on A to a point at which I am confident it was working
I have rebooted both A and X
I have cleared all the IE cache on A

This issue has just started a couple of days ago without me making any changes that I am aware of - though I bet you have heard that many times before!!

The problem is not the end of the world, but it is bugging me immensely.
Has anyone got any ideas that don't include me downgrading from Win7 to Win10!!

Thanks.