Shortened incoming CLI on M3820's and DECTs only

[brgf11]

All,

We have a customer who is stating that incoming CLI on international calls do not show the leading 00, only the country code and tel nbr (e.g. 44 207 321 1234)
instead of 0044 etc. Consequently they can't call them back automatically.
This is only happening on M3820's & DECTs not on M3904s.
This is a totally unknown area for me, so any assistance is much appreciated.

Thanks
Jimbo

 

[brgf11]

Customer has no advised that this problem is across the board - this is affecting ALL display phones!