HTTP ERROR 500 related to Defender and BeTheme

After trying to update the WP version of my site via Installatron, on cPanel, I am getting a HTTP ERROR 500 on the site if Defender is enabled along with Smush or Hummingbird and if having the BeTheme active with it.

I checked it and the issue is not there if switching to Twenty Nineteen theme. And the error only appears on the admin, the front-end loads fine.