This problem sounds somewhat similar to mine, which is with the LEGO command line client directly, which presumably uses its own library.
I created an issue with the LEGO client because I was mistakenly thinking that it was checking the wrong name servers, or checking them in a wrong way, but after some more research this turned out to be false: Possible bad propagation check with dns-01 challenge · Issue #1777 · go-acme/lego · GitHub
In my thread here on this community forum, there were some people who thought that my company's DNS setup was too complicated: Was there some dns lookup failure in recent days? I personally have some doubts about it (it's not like all servers should work for a correct result, one at each step is enough), but the "dns server department" has made some changes anyway. In about a week we will need a renewal and we can see if it works better now.
But since we seem to have somewhat similar problems, this may be a hint that the real problem is not with you or with me, but somewhere in the range < us, Let's Encrypt ].