Separate a surface film from a persistent cloudy pane
DASMA describes condensation when humid air encounters a colder surface, including on some multi-pane glazing. Persistent fogging can have a different cause and may merit inspection for a glazing-seal issue. Do not remove glazing or trim to investigate.
Give the technician a useful record
Take a photo from the normal floor position and note indoor or outdoor surface, time and recent weather. If you cannot tell where the moisture sits, say so. That uncertainty is preferable to ordering a replacement pane based on an assumed seal failure.
Keep the repair compatible with the door
Have the window design and door model identified before any replacement. A glass change also needs to suit the door assembly. The goal is to address the observed moisture problem while preserving the correct glazing and section configuration.
Your questions
Does condensation prove the window has failed?
No. Surface condensation can occur without a failed pane. Persistent fogging or recurring unexplained moisture needs a professional assessment.
Should I drill a hole to let moisture escape?
No. Do not drill or alter the glazing or door section. Ask for an appropriate diagnosis and compatible repair.