Why is the Google Play Store showing wrong app sizes?

Since recently, the Google Play Store is showing different app sizes when downloading updates. The displayed size of the update is X but the downloading size (of the se update) is slightly greater than X. For example (see attached screenshots): - Messenger (FB): 44 MB -- 25% of 46 MB - Microsoft Teams: 37 MB -- 29% of 39.01 MB - Spotify: 34 MB -- 32% of 36.10 MB - Uber: 49 MB -- 22% of 51.00 MB - etc., etc., for every other update Is this a recent bug in the Google Play updater? Or might it be an indication that I have a virus or spyware installed on my phone? > .. Some more examples, comparing the size in MiB to the size in MB, as @Robert suggested in his answer: > My main question is: Does anyone else has this issue on their Android phone?