1 extension/trunk has weak secret

Hello

On my FreePBX 12.0.1rc20 System Status panel I can see a warning message:
1 extension/trunk has weak secret

Warning: The use of weak SIP/IAX passwords can compromise this system
resulting in toll theft of your telephony service. You should change
the reported devices and trunks to use strong secrets.

SIP Trunk: sipprovider / Secret less than 6 digits

I did have this trunk configured but deleted it but system still detects it.
Where do I need to check for information related to the trunks that may be causing this behavior?

Thank you in advance
dawidku