Please provide more details for your issue.
- 3CX version
- Type of lines (BRI or PRI)
- Brand/Model of gateway
- Gateway debug log
- 3CX Console log
Where are you set the calling party ID? Outbound ID? Gateway's Digits Map?
What "caller ID" set on your 3CX?
What number display on your called phone? No number or Main number?
We cannot guarantee to fix your issue. But the above information may be help to fix your issue faster.