letsencrypt – The SSL certificate of Let's Encrypt Wildcard does not match the domain name

I have a problem after the installation of the Let's Encrypt Wildcard Certificate, maybe someone can help me.

I installed a wildcard certificate generated by sslforfree.com in cPanel.

The domain is fluidpower.pro and in the hosting, this is an additional domain.
Certificate works for fluidpower.pro but it does not work for any subdomain that you created in cPanel.

In the cPanel Certificate Details I see that the certificate is generated for both the subdomains and the domain:

Certificate ID: _wildcard__fluidpower_pro_b5553_5b59f_1560821893_33f836cd985519af6b2aec555b1a5f0d
* .fluidpower.pro
Issuer: Let's encrypt
Key Size: 2,048 bits (b5553b52 ...)
Expiration: June 18, 2019 1:38:14 AM

But when I try to go to some subdomain, for example test.fluidpower.pro I have a mistake NET :: ERR_CERT_COMMON_NAME_INVALID

I checked in `whynopadlock.com` and found this explanation:

Your SSL certificate does not match your domain name!
Protected domains:
* .prod.iad2.secureserver.net

Can anyone explain why it happened? Why does the certificate protect strange domains when running any subdomain, but does it protect the primary domain well? How to solve the problem?