rendering errors

Hi,
My site doesn’t look well anymore i think until WP5.3 upgrade. (i didn’t change nothing except the WP core version)
i’ve deactivated all myplugins (except Akismet).
Theme slider doesn’t work, the three pics are shown one under other and don’t silde.
a big blue toogle before my menu.
I’ve asked for a restore to my host support, but i’d like to get answers to those issues
Thanks a lot for your answers

The page I need help with: [log in to see the link]