Record Not Saved

Hello,

I have a user reporting issues with saving a record.  This appears to be sporadic, but has occurred more than once.  This is saving from an 'old' form. She receives a message similar to:

Red notice: “ unable to contact Quickbase to avoid losing work. Please leave this window open and try again in a few minutes.”

Does anyone know what scenarios would result in the above error?  I tried reproducing by disconnecting WiFi; however, I received a different error.

Thank you!