Mag 250 remote working intermittently

Hi there

P am a newbie at this so any help is much appreciated.

I have a Mag250 (x2) both bought on ebay.

I have portals loaded but remote freezes quite a lot and box wont do anything.

Works fine on magic remote.

Any suggestions greatly appreciated

Thanks

Sorry also meant to say works fine on set up etc. only problem when in portal.