I've tried various things to force https, but nothing seemed to work, and some changes made things worse
e.g.. suggestions here
https://www.phpbb.com/community/viewtopic.php?t=2271756
OpenGD77CSV error importing and appending CSV's
Re: OpenGD77CSV error importing and appending CSV's
I have tried changing the .htaccess and it may now be redirecting HTTP to HTTPS