Thank you, I reverted to a previous image, and is working now. The issue presented after I enabled the wlan and reconfigured pihole to the fixed wlan ip address instead of the eth0. This time every thing went ok, I had tried at least 8 times before. Don't know what I was doing wrong before.
A weird issue remains only on my main pc (Mint) I get he DNS server assigned to 192.168.1.158, 220.127.116.11, 18.104.22.168, the pihole is on .18 and the dhcp available is from .100 to .250. If I manually set it to .18 it does work fine. I guess is something residual, I have deleted the network connection to no effect.
$ nslookup pi.hole 192.168.1.158
;; connection timed out; no servers could be reached
Thank you, I do have it as my DHCP server, and the one on the router deactivated. Unfortunately the router has no option to modify or turn off the DNS server, I counting on it being deactivated along with the DHCP.