Please also add
DEBUG_API=true
in your /etc/pihole/pihole-FTL.conf and run
pihole ftl tweak/more_resolve_details
to receive a modified version of FTL that should show a lot more debugging messages related to host name resolving.
Please re-run
echo “>reresolve >quit” | nc 127.0.0.1 4711
afterwards and check the output in /var/log/pihole-FTL.log.