Ideally it should not update the phase/project progress when updating the other fields. It is happening for a project which has at least active phase and is not update on the day of testing. When updating spentBudget or budget fields (or may any other allowed field update in the phase edit form), it updates the progress of the phase. Most of the time it actually reduced the progress.
fyi @RishiRajSahu
Aha! Link: https://topcoder.aha.io/features/TCCONNECT-403