I did not send any further updates because I had not received any advice or suggestions from you to try, even after sending in the requested export of my form. If you don’t have any answers I understand, but future readers of this thread should realize that number truncation is NOT a resolved issue and there seems to be no known fix.
I’m sorry to hear you marked this as resolved, because I am experiencing exactly the same issue, and NOT only with email confirmations. It also appears in on-screen submission confirmation messages, e.g.
Optional additional donation to American Midwest Ballet: ${number-2}
Oddity: The behavior affects ONLY numbers with four digits or greater. Thoughts?