Periodic "Non-JSON error body" error message

I’m uploading pictures from Appgyver to Xano. Occasionally, I received the “Non-JSON error body” message when attempting to upload a picture.

I run it again, it works without a problem.

I put it into a loop, such that a failure of the image upload restarts the upload and eventually it will work, with the same set of inputs.

Any idea why this feature would periodically fail and periodically succeed? Has anyone else had this issue?