I’m on the latest iOS version and I’m experiencing the same. However, my wife is a few minor versions behind, and her‘s is much more accurate.
During the pandemic, commercial air traffic plummeted. While it has returned to normal levels, it seems the models are still missing some historical data.
At the end of the day, most of these tools are simply displaying NOAA data in the user friendly format.
Seems that mine old versions are much more accurate.