Just re-install/reissue them, then wait up to two hours for Apache to restart.
An issue we had with nginx yesterday broke some of the SSL certificates.
Did you create an A record called webmail? If your t goal is to make webmail.papale.my.id work, you need to create that record. The value is the same IP address as the main A record.
Once you create it, you might also want to re-issue your SSL certificate in order to have the webmail subdomain included.
Default web page is often caused by DNS and the account having mismatched IP addresses. Verify that the A record in cloudflare matches the one shown in Plesk, and if not, update CF to match. After that it may take a few hours for the DNS change to propagate and take effect.