I noticed that for the last month or so that indoor runs and rides are not being counted towards intensity minutes. They’ve shown up in the past, but now they don’t. I have my heart rate zones set up properly, so I don’t know why this is happening now. I didn’t change any settings. 
I’m very confused as to why that zone 1 bar is so wide compared to the others.
To revisit this, for what it's worth, the grey segment in my Heart Rate tile looks very similar to yours.
My zones are based on HRR%, with all the default percentages:
zone 1: 50-60% [in my case: 122-135]
zone 2: 60-70%
...
zone 5: 90-100% [in my case: > 180]
So again, I don't think a huge grey segment is anything out of the ordinary, it's just a consequence of the fact that Garmin graphically combines zone 0 and zone 1. [Which is clear from the fact that in this screenshot, my HR is far below the zone 1 minimum of 122, yet the grey circle which indicates my current HR is still present on the graph.]
Seeing as how zone 0 is so huge [ranging from 30 [*] to zone 1 minimum], I don't see how any user could *not* have a huge grey segment [compared to the other segments], unless their zone 1 starts around 60 bpm or so.
Personally I think Garmin should graphically distinguish zone 0 and zone 1 in both the watch and Connect app, but for whatever reason they don't [except for the fact that zone 0 is omitted from the time in zones chart]. If they did, then the hypothetical segment for zone 1 would look fairly normal compared to the segments for zone 2-5.
[*] as mentioned previously
