When our hotspot is enabled we cannot send a packet bigger than the MTU setting on the hotspot interface. This is causing some network applications to be very slow. Has anyone else had this problem?

what you mean by very slow, and whit is the value of MTU?

Well if we set the MTU on the Interface to 1500 and try to send a packet sized say... 1600 it will drop the packet rather than fragment it. If I disable the hotspot then do the same test the packet will go through.

It will take minutes or longer to load some websites versus seconds or less with the hotspot disabled.

I don't believe I've set any unusual settings in the hotspot config...

I'm using RADIUS as one of my authentication methods but I've tried my test with logging in with a hotspot user and it still doesn't work. I've also tried adding the destination test IP to the walled garden and it doesn't make a difference.