LOTS of erroneous "max speed" numbers

When I look at the graphic view either here or on Polar Flow site they are not showing as spikes in pace. So just what is causing this?

[SOLVED] It seems I just need to crop out a tiny bit of data at the end, about as much as the line is thick. A couple I had to crop of a bit at the front end.

My real max speed is just over 10mph (I’m 70 YO)

That’s caused by inaccurate GPS signal.
Make sure to wait long enough for your watch to get a good stable GPS signal, before you hit the start button. And make sure to stop your activity before going inside where GPS becomes faulty.