I have this weird issue, mail seems to revert cpanel/webmail. Fresh install of hestiaCP evereything worked just fine i was able to access roundcube mail yesterday now it is just reverting to cpanel/webmail and says login credidentials are wrong.
Any idea what is behind this error?
Do you mean that yesterday webmail.yourdomain.tld was pointing to roundcube installed on Hestia but today it points to Roundcube installed on another server?
1.- Check DNS.
2.- Remove history for your webmail domain in your browser or use private/incognito mode… or another clean browser.