400 Bad Request

Hello, i’ve got 400 bad request errors on test page after a couple hours.

Can anyone help?
test page; https://1d5pwbc9pshla.cdn.shift8web.com/wp-content/plugins/shift8-cdn/test/test.png

debug info;

Shift8 CDN Debug Info
WordPress Version: 5.7.2
Current WordPress Theme: Salient version 13.0.5
Theme Author: ThemeNectar - https://themeforest.net/user/themenectar
Theme URI: https://themeforest.net/item/salient-responsive-multipurpose-theme/4363266
PHP Version: 7.3.13
Active Plugins:

Akismet Anti-Spam (4.1.9)
Lottier for WPBakery (1.0.2)
Really Simple SSL (4.0.15)
Salient Core (1.8.2)
Salient Demo Importer (1.3)
Salient Home Slider (1.4)
Salient Nectar Slider (1.7)
Salient Portfolio (1.7)
Salient Shortcodes (1.5)
Salient Social (1.2)
Salient Widgets (1.2)
Salient WPBakery Page Builder (6.6.0)
Shift8 CDN (1.57)
Webcraftic Robin image optimizer (1.5.4)
Yoast SEO (16.6.1)

Love the Shift8 concept and wish all the best for the project.

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