I don’t know whether this is a bug. All of my activities have always graphed correctly on the activities calendar, now I have suddenly have two that are not. It is a little hard to explain, but this screen-shot shows it. Feb 10 and 11 don’t show the ride graph and statistics, but all the others do.
If I manually download the activity from Garmin Connect and then upload it to intervals.icu, it displays correctly. I think these may have uploaded from Strava, so I’m wondering whether it is related to that?