Often I’ll press a key to select something and immediately issue a command reflexively. Like “3”, “right-click” to move group 3 to a spot. The issue is that if there is nothing in group 3, then whatever I happened to have selected will be given that command instead.
This applies to “Select next idle economic unit” and “Select next Scout unit,” “Select all idle villagers,” “Select all idle military units,” and anything else that’s intended to select something specific (i.e. not ctrl-A). In all cases, I’m no longer interested in keeping the previous selection. It has no use to me and only downside potential.
I can understand that some may not consider this bug, but to me, the expected behavior is different from the actual behavior. That may or may not be by design.