Not all google sheets column represented in flow

Not all google sheets column represented in flow

Is there a limit as to how many columns are imported and represented in a flow?

I have a google sheet with around 140 columns in it. when I try to use ZOHO Flow to drop all new rows to a custom module I've created, I can only see around 40-50 of the columns that I can then map to required field.

Any suggestions / Enlightenment?

Thanks
Dor