tl;dr - Garmin, I think your metrics buffers need fixing in the Fenix 5 Plus line (details below)
I've been thinking about the issue of Stride Length, Vertical Ratio and GCT Balance dropping out from the HRM, and on my run this morning I changed a few things (phone connectivity etc) during the run with no noticeable effects on the data. I don't believe this has anything to do with bluetooth and ANT interfering with each other as previously suggested by some people.
As someone else already mentioned, my data also drops out at exactly 2:08. Now I'm pretty sure the HRM produces a sample set once per second (which may then be transferred individually or as blocks over ANT), but 2:08 is 128 samples... (a significant number in computer terms - e.g. the maximum size if the index for a buffer was a signed byte).
Looking at the *content* of the data, I do believe this the watch is reporting (and most likely only storing) the FIRST 128 samples rather than only the most recent set (look at the Vertical Ratio in the image below - the drop from high suggests starting running).
So Garmin - can you diff your Fenix 5 Plus code branch with the Fenix 5 branch around the area of metrics buffers and check that they're being indexed right please. ciq.forums.garmin.com/.../1398072.png
