Calling Blueface No from Voxalot does not work using Grandstream, works from SJ-phone

[kurun]

Calling a Blueface account from my Voxalot account using a Grandstream SIP device (GXP-2000 or HT-286) does not work.
I get Code 481 on the IP-phone screen.

When I call using the same Voxalot account logged on in SJ-Phone, it works.

There is a Blueface test number (the Monkey sounds) that one can try (*266)-300 or 300@blueface.ie

I would appreciate if anybody out there can check this from their Gandstream device, and confirm the problem.

Calls to Blueface via sip-broker used to work fine before.

Any suggestions would be appreciated.

Thanks