Mystery solved. 
I totaly forgot that some years ago I was messing with my router NAT settings and it was redirecting all dns requests to correct dns server. So that machines on my network would not call dns like 8.8.8.8. 
For example a call to 192.168.0.5:53 (which has no port opened) would end in 192.168.0.1:53 which has port 53 opened.
Disabling this feature shows correct results from nmap.
Why am I doing things like this to myself? 
