Edge 530 stops recording data just after starting Strava starred segment

On two occasions now my new 530 has in effect frozen approximately 16 seconds after starting a live Strava segment that has been starred.

No distance, no HR,, no cadence etc. It still manages to store the actual GPS location and the timer keeps going, such that I get awarded KOM's and Flybys shows the full journey.

Incident 1 was only 1.4km from home and granted I started the timer the second I got out of the garage on a very overcast day. It was recording and reporting fine up until starting the segment. The live feedback still worked because the entire segment (12.5km long) it told me how I was tracking +/- seconds etc and immediately reported "PR" at the end. Then I ntoed it was still reading 1.4km (or a bit more because it froze 16 seconds after the start). and my average speed was reported at about 4kph vs the 45 I had just been doing.

Last night same thing it was different in that it stopped recording about 15 km after the start, but again 16 seconds after commencing a starred segment, However I had already passed through earlier segments without issue. Clear skies last night.

It's frustrating because although I get awarded official split itmes there is nothing to compare against (flat lines etc).