It sounds like you are having server problems. ie your server is losing connection, connection is timing out, server is overloaded, etc. Or another plugin installed on your website is causing this problem. BPS does not do anything directly or affect saving or editing page content – creating posts or pages.
Do the standard WordPress troubleshooting steps to determine if another plugin you have installed is causing this problem.
1. Deactivate all your plugins except BPS and test.
2. Deactivate your plugins one by one and test.