Deactivating and reactivating the plugin

When this plugin is deactivated and then reactivated, the 404 page gets switched to the homepage, even if that was not the redirect page before deactivating.

Example:

Before deactivation, 404 redirects to https://yoursite.com/sales-page
After deactivation then reactivation 404 redirects to https://yoursite.com

This should not happen; the plugin should remember the original setting.