Question on budgets

Our budgets are changing without user input ( that we know of). Certain GL accounts will update with actual data from our financials an insert them into the budget and save this change unbeknownst to us until we run monthly financials and have to enter the budget again. 

When we run an audit report, no one has logged any change in the budget since the last date we fixed this issue

It has happened each of the last 3 months.  

Has this happened to anyone else and if so what was the issue?