When I am on the [Planned Spend] page, and I click "edit expense series" for an existing category, change the amount, and then this change will randomly revert back to the old dollar amount sporadically.
For example, if I have home set as $1400, sometimes it will revert back to $1100. I then change it back using "edit expense series" from the Spending Plan to $1400. It will save but then randomly change back.
I haven't tracked it super closely, but I think it's when a new month starts.