Turn off SSL cPanel redirection:

SSL redirection can be found in WHM >> Tweak Settings >> Redirection

When a user visits /cpanel, /webmail, /whm, or visits other URLs that redirect to a cPanel service, the system will redirect to an SSL URL for the closest matched domain that the system has a valid certificate. If you disable this option, the system will redirect to the equivalent URL that they visited based on the original request made via HTTPS or HTTP. This option also controls how the system will redirect unencrypted cPanel, Webmail, WHM, and DAV requests to the best matched certificate for the domain when “Require SSL” is enabled. When enabled, it will redirect closest matched domain that the system has a valid certificate for. When it is disabled, it will simply redirect equivalent HTTPS URL.

Always redirect to SSL [?] On Off = off

Non-SSL redirect destination

When visiting /cpanel or /whm or /webmail WITHOUT SSL, you can choose to redirect to:

Origin Domain Name
Hostname

Origin Domain Name default

SSL redirect destination = Origin Domain Name
SSL Certificate Name default
Hostname
Origin Domain Name

 

Logout redirection URL = No redirection default

If you would like for the domain.com/cpanel to work again:

Modify WHM >> Tweak Settings >> Security
Require SSL = off

or

Modify the /var/cpanel/cpanel.config file setting
requiressl=1
reset to
requiressl=0
and restarted cpanel