Static browser cache header cannot be activated

If I choose to activate static browser cache headers, they are activated, but as soon as I reload the cache settings pages in WP the option is disabled again.

So how can I fix it to keep it being activated?

Best

Activation of headers: https://imgur.com/zS3i27z

After reloading cache settings page in WP: https://imgur.com/L7uTyas

• This topic was modified 8 hours, 48 minutes ago by hirschferkel.

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