Can’t delete staging sites

Hi, I’m getting the following error.

Something went wrong! Internal server error while processing the request! Go to WP Staging > Settings and lower ‘File Copy Limit’ and ‘DB Query Limit’. Also set ‘CPU Load Priority to low.’Than try again. If that does not help, open a support ticket

I’ve tried changing the settings suggested here, but the same error would occur.
https://wp-staging.com/docs/wp-staging-settings-for-small-servers/

And my current PHP Memory Limit in WordPress is 256m. I tried 512, but the same error comes up.

How can I go about deleting them? I’ve got 4 built up now…