Can't say I have seen this.   Have you tried rebuilding key files followed by rebuild sort files for the bank rec module?

yes i upgraded them from 4.5 to 2015, i rebuilded and sorted every bank rec file in all 10 companies.    had them purge old data in old bank codes.    advised them to clear at the end of the month when they are in balance.  this seemed to help.   but one user does not want to do this because she likes to do it right before starting the next bank rec.   

it is a similar behavior to when you enter a deposit or an adjustment and then you delete it and it doesn't subtract/add it properly from the bank balance.   i have seen this one at multiple places.

but this is different in that it is always the first record.   it's weird that it happens even if no other activity is occurring.  it makes me wonder if when printing the bank reconciliation report fro the reconcile bank screen if there is some kind of recalc going before that that is flaky.