[mercora]

i had this issue but i just set the time to wait for propagation high enough to be somewhat certain and had no further issues since (its 10m i think). it does not really matter to me how long it takes as its an automated process... should be finished before expiration though ^^

having multiple nameservers is pretty standard and often mandatory requirement set by the NICs. Its just that my secondary is sometimes not fast enough to transfer the zone after a change notification which triggers this issue.

Also, retrying after an authoritative nameserver said there is defacto no record seems pretty wrong to me... i doubt they use google DNS or anything really. in order to avoid caching issues they very likely resolve names recursively without (the usual) caching