There is an ongoing issue with the .top TLD currently. See https://letsencrypt.status.io/.
There are also a few threads about this issue on the Community already. The most relevant is probably DNS problem: looking up A for xxx.domain.top: DNSSEC: DNSKEY Missing; no valid AAAA records found for xxx.domain.top - #31 by mcpherrinm where the Let's Encrypt staff provides updates.
Please don't post "I'm having this issue too!" in those thread(s) as it doesn't really help: the issue is known already and I'm pretty certain everybody using the .top has issues.