Forerunner 265 Always Detects Freestyle as Breaststroke

I’m using a Garmin Forerunner 265 and I’ve noticed that whenever I swim freestyle, it is always detected as breaststroke.
This happens consistently even though I’m swimming with a pace of 2:30 per 100m over a distance of around 1000 meters. I’m using Pool Swim mode and the pool length is correctly set.
Is this a common issue? Could this be a sensor problem or is it likely due to swimming technique?
Appreciate any advice or suggestions!