Hi marcerlser,
from time to time I encaunter nealry the same problem with my Turris Omnia. local names aren’t resolved but other resolving seems to work as expected.
It turns out, that after software upgrades I need to reconfigure my Turris’ DNSMASQ daemon. In my case it forgot the setting of the listening port. (http://turris.lan/cgi-bin/luci/admin/network/dhcp --> Advanced settings --> DNS server port) The field was empty. After reinserting DNS default port number “53” everything works like a charm again.
I guess external resolving works for me because I have three DNS server addresses set up to be advertises to the dhcp clients. First one: turris ip address, second one my internet gateway (which is not turris) and third one: an OpenDNS IP. So If the dnsmaq port is not set up properly in my network infrastructure, ths DNS request will be forwarded to another IP but turris which causes every resolve request but the local names to work fine.
Hope that helps.
Kind regards
ChrisPHL