There was no mapping at all for the before send, and when I added it in, everything is working perfectly!
Thank you for your help!
I have just wasted hours going round in circles with this. Finally re-read this post for the fifth time and understood whats going on.
Suggestion, if deleteing the 'Before Send' 'Mapping' option is going to break the entire service call, would probably be a good idea to make it non-deleteable.
Yes you are right Appery.io DB API will generate an error if you will try to send incorrect format for "date" type field.
Note: correct format for "date" type field is "2011-02-15 01:02:03.004"