Our resolvers (especially in Chile, Singapore, and Taiwan) are not getting timely responses from your name servers, which appear to be hosted on Linode VMs:
$ nsips mali-interest-hub.com
ns1.thehostelry.net 14399 A 188.8.131.52 ; li190-103.members.linode.com [AS63949]
ns2.thehostelry.net 14399 A 184.108.40.206 ; li1502-132.members.linode.com [AS63949]
ns3.thehostelry.net 14399 A 220.127.116.11 ; li198-26.members.linode.com [AS63949]
ns4.thehostelry.net 14399 A 18.104.22.168 ; li238-168.members.linode.com [AS63949]
Especially since these are all located on a single AS, routing issues could be a single point of failure for your DNS. I strongly recommend that you arrange for secondary DNS coverage from another DNS hosting service, there are several free secondary DNS services, both Hurricane Electric and NS1 are quite good see https://www.keycdn.com/blog/best-free-dns-hosting-providers.