@Adarre I can only tell you that Wildcard certificates sometimes cause issues. It‘s the same with subdomains, aliases… Sometimes they‘ll get lost.
I think it is caused because of DNS cache.
Here is the why:
1. Plesk / cronjob automatically updates DNS policy with new ACME policy
2. Then the croniob sends the request to Let‘s Encrypt, that is pushing back the DNS verification (in case of wildcard!)
3. Soemtimes this DNS answer is not yet the latest one
4. Lets Encrypt declines the request
5. Server creates .acme-challenge Folder to do non-wildcard verification
6. File based verification has no caching, therefore it is approved immediatly
I‘d highly recommend to not use wildcard certs OR to switch to a professional certificate.
Sorry I cannot tell you more, but we have around 600 hosting customers here - and always issues with Let‘s Encrypt wildcard certs.