The latest bug my customers encountered was a calendar bug: On every date type field, the calendar was wrong - for example October 5-th 2020 was on Saturday instead of Monday. Think about it: every date in the system was WRONG! This happened overnight when Microsoft teams has decided to push an update.

This went on for more than a week! It is absolutely appalling when a company like Microsoft releases updates that literally break the product. Unfortunately this happens often lately.