Cannot delete log

After sending to analysis and get result of “file is safe”, I’m trying to delete logs by clicking “Delete from log”.
But even if I click “Delete from log” or check and choose action “Delete from log”, I cannot delete.

I did below however still cannot.

1. Uninstall “Security by CleanTalk” from WordPress, re-install, perform scan, send to analysis and delete.
2. Clear scanner log, re-scan, perform scan, send to analysis and delete.
3. Tried different browser, Firefox and Chrome.

It’s appreciated to let me know how to safely delete log.