This seems to be an issue with the Freenom, who runs the .cf TLD.
$ dig mrks.cf
...
;; Query time: 1030 msec
$ time dig mrks.cf NS
...
;; Query time: 1020 msec
dig mrks.cf NS 0.00s user 0.01s system 0% cpu 11.039 total
In fact, the lookup for the .cf root servers is slow:
cf. IN NS
;; ANSWER SECTION:
cf. 0 IN NS d.ns.CF.
cf. 0 IN NS a.ns.CF.
cf. 0 IN NS c.ns.CF.
cf. 0 IN NS b.ns.CF.
...
;; Query time: 2640 msec
dig ns cf 0.00s user 0.00s system 0% cpu 7.655 total
and trying to query your domain’s authoritative records via the official nameservers themselves leads to connection timeouts:
time dig mrks.cf NS @a.ns.cf
;; connection timed out; no servers could be reached
This is corroborated by dnsviz mrks.cf | DNSViz
When I dig via the authoritative CF nameservers (dig AAAA mrks.cf @ian.ns.cloudflare.com), the lookup is instant.
All in all Freenom is a free service and there are countless examples on the forums here showcasing issues with their servers. You might want to consider a different top-level domain for your site.