Mitel Phone Manager not connecting

[Hibs1969]

I have a customer who is using SkyHUb Router - They have a Mitel Phone Manager Softphone which is not registering.  I have used the Phone manager with end users credentials on my home broadband (Virgin) and it works. Any ideas on settings to change, SIP ALG is turned off.

All help appreciatted

[jamesn123]

@Hibs1969 

Have you tried asking them to switch off Sky Shield?