Letsencrypt - again :(

Yes. wait until OS updates it in the package.

It (LE) works as is for most (if not all folk)

There is a good reason why wildcard certs are not a good thing to use. (Joe gave this in some earlier answer (I cannot remember where exactly, without the effort of doing a search here https://forum.virtualmin.com/t/lets-encrypt-wildcard-certificate/121146 and elsewhere)

If Web-based validation fails it is usually because your web server is not permitting the LE to place its temorary file in the .well-known so check that.