It is indeed a known problem:
As far as I can say, the issue does not occur anymore with new updates (the user just has to wait a few hours until the calculations for the updated city are complete - I guess most are either a bit impatient or haven’t noticed yet that the update notifications come before the slow jobs are over) but there are streets that have not been updated for a year or more, and they can be marked as completed if they were over 90% at some point even if they are now under 90%. I have re-run most of the cases I was aware of (hard mode style) but I think I still have 6 of those.
If @pettersunde has examples involving recent updates, that’s very interesting because I probably check around 2000 streets/month and don’t have any.