Hi, I have the same problem, what additional information do you require to help me with this problem?
this is my version of php:
PHP 7.1.33-17+ubuntu20.04.1+deb.sury.org+1 (cli) (built: Aug 7 2020 14:47:49) ( NTS ) Copyright (c) 1997-2018 The PHP Group Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies with Zend OPcache v7.1.33-17+ubuntu20.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies with Xdebug v2.9.6, Copyright (c) 2002-2020, by Derick Rethans
and this is my version of apache:
Server version: Apache/2.4.41 (Ubuntu) Server built: 2020-04-13T17:19:17
My problem is the same, when activating the Option "Activate SSL on all pages" the Administrative part of Presta Shop does not allow me to make any changes and every time I save, I redirect to make login, while having this option enabled if it works for me perfectly the Store on the Client's Side and I do not get the Error of "ERR_TOO_MANY_REDIRECTS", when through the database I disable the option "Activate SSL on all pages" the opposite happens, if it saves me and the administrative part works perfectly , but then the client-side store stays at "ERR_TOO_MANY_REDIRECTS" I hope I could have explained better xD Thanks in advance