That is rather strange, it’s certainly not behaviour we have seen in house.
When you say the events are defaulting to 1 minute long, are you referring to being zoomed out to see 1 minute worth of the timeline, or have your multi-sounds been extended to 1 minute?
Events will “finish” when there is no more sound being output. So if your multi-sound stops outputting audio, the event will be considered “finished”. If there is a reverb tail or a delay effect anywhere in the event, it will keep it alive until it has finished.
The length of an event isn’t dependent on how long the timeline appears in the event view, nor are they “baked out”. The length of an event’s timeline depends on the audio assets, sound modules, and effects used.
Also, it is not possible to bulk edit events the way you described. “Resize to Contents Length” only works on valid sound modules.
Could you provide a screenshot of an affected event for me to see?