Contao 4 https and backoffice url pb

Hi there,

i'm having an issue i don't understand.
Website is hosted by OVH, (shared hosting), i'm running Contao 4 on it.
i did a htacces redirect, to redirect non https to https.

Code:

---

RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

---

it works well for frontend.
but when trying to go to backend, :
https://myawesomewebsite.com/contao becomes : http://myawesomewebsite.com:443/contao/login

but if i write : http://myawesomewebsite.com/contao/login, it works.

Also i had to overwrite the fe_page and be_main/be_login, an edit the <base> tag because contao gave me the non https version.
any clue/advice on this ?
it used to work well a few weeks ago
i tried to update (composer update), to clear contao cache (width contao-console)

Thanks