DKIM after migration

Hi,

I have this issue, after migration from 12 to Onyx (centos5/12.05>centos7/Onyx), I'm getting this in maillog:
dk_check[30583]: DKIM verify result: DKIM verification (d=mydomain.xx, 1024-bit key) failed: signature verification failed

After checking with dkimvalidator i got this:

Message contains this DKIM Signature:
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mydomain.xx;
s=default; t=1476796694;
bh=jBHu0RF4c0DzohwyrlCCm+LHXTp77ZYWvhhB0smAp2c=; l=14956;...

DKIM after migration