..[UPDATE] ......Also I should actually note guys, that this only happens within certain browsers "AND" certain actual operating systems. For example this SSL error doesn't even happen when using Windows 8 w/Safari web browser. but however "DOES" mysteriously error when using Windows 'XP'...
I can confirm that this issue has seemingly re-appeared again after the latest 11.5 update. I had Plesk Panel 11.0.9 before and never ran into this specific issue, but have noticed however that after the 11.5 major update, with all the new NGINX features etc., this problem for me has re-emerged...