I’m going to shamelessly drop a link in here, (where a few Monzo staff have commented and might be notified…) to a post of my own that would have been a complete non-issue if this feature were implemented.
TL;DR - If I add everything up it does not come to my balance, this has been the case over a long period of time, and another user reported having the same experience.
I hope and assume it’s just that something I did spend is missing from the feed, if I was missing much more (it’s about £7) I’d probably be more angrily pursuing a solution, but I am surprised not to have had a 
response at all, since 11 May.