I originally posted this here but it turns out, I have a different problem.
Since two days, i cannot create or renew any certificates for niyawe.de. (DNS problem: query timed out looking up TXT for _acme-challenge.aaaaaa.niyawe.de) While I can create new certificates for niyawe.tk.
I use dehydrated with a dns-hook-script and the same nameservers for both domains.
My hosting provider is Hetzner. Since this is a common question: I am also not blocking any IPs.
The last successful renew for niyawe.de was on 2020-04-29. I haven’t changed anything on my side since then.