SSL Support for FULL STRICT behind Cloudflare

hosting with so many other companies using multiple cpanel like spanel , directAdmin, plesk etc. i see this issue only spanel where when i mark a website to full strict it either

1. doesnt work and shows https://prnt.sc/sHEABJlQOms3 ERROR 526 host error https://prnt.sc/9QP4fI19MFSk making it flexible solves the issue but i need full strict

2. even if we make it work with full strict then there is a work around to make it work then every 3 months it fails to renew the certificate  as lets encrypt cannot find the IP as its behind proxy i dont face this issue with anyone panel but spanel there should be a fix as having over 2000 sites no member of our team can just sit there to renew every 3 months