I did both of these at once last week.

Added a breakpoint. Debugger didn’t break.

Added an echo "here";. Debugger didn’t print.

Added a throw new Exception('fuck');. Debugger didn’t throw.

Stepped through. Debugger wouldn’t let me step in.

It took me almost an hour to realize it wasn’t the debugger’s fault and that a variable I thought was guaranteed to be truthy at that point was actually falsey due to upstream changes in a spreadsheet parser. I felt kind of stupid for not trusting the debugger at that point.