Edge 1030 V10 calculates elevation to high

I have same issue, one ride reported 1070m, but after elevation correction in Connect, went down to 710m, so overestimate by 50%!   I reported this to Garmin & told to do various things for the GPS, none of which helped. Contacted again & they then said to return unit for a newly refurbished one!  After seeing more reports of elevation issues on 1030 Facebook group, all since 10,0 update; so I called them a 3rd time; they now seem to acknowledge there is an elevation issue & told me NOT to send Edge back to them while they investigate.

I checked all my 7 rides since the 10.0 update, all changed significantly when correction applied, checked last ride before 10.0 update and correction changed the elevation very little.

So hopefully some new firmware will be out to sort out this issue.