I receive a "failed to send" message on one data input in a form but the feature is being updated with the data that "failed to send". I have the same dataset in a field map that updates without a error message and the other feature in the QC form doesn't trigger the message when sending. I sent the .qcr to myself and can only see "unknown error", all the relevant data appears to be correct. In the grand scheme of things it's not a huge problem, I'm getting my data but it is annoying to have to discard the information every time and feels like a gamble.
@BrandonSwanson - Could you send the .qcr file to quickcapture@esri.com and I'll take a look.
Also, is this ArcGIS Online or ArcGIS Enterprise.
Happy to troubleshot this for you.