Hi Joe, I've had similar errors when the page is trying to pull in too many records (ie thousands) from the server. Are you able to limit the number of rows/records in the model using its Advanced properties?
this might depend on how many records your users need to work with, but they can always use the 'load more' button to bring in more records if required.
We ran into the same issue on this today. What confused me was that we were only getting the error on some of the records for the same custom object.
Our primary model was for a custom object "Property Listing". The page loaded that model as well as a few others (attachments, photos and activities).
HOW WE FIXED IT:
Apparently the "Attachment" model was the culprit. We had it set to load 20 records when the page loaded and when I reduced it down to 1 the error went away. I haven't messed with it to see at what amount of records the error will show up again as we only need to load a single attachment record.