I did some research on this and discovered that this (like so many of the other problems I encounter on Garmin Connect) is a
known issue on Garmin Connect (NOT a GOTOES bug, which is why you do not see this on other platforms).
So, the solution is to log into your Garmin Connect and correctly set the activity type. In your case, that would be "eBiking" (see Screenshot below).

- Detected as "Other" By Garmin Connect and must manually be changed to "eBiking"
Garmin is detecting your activity as "Other," and that type of activity does not have cadence. I double checked the output file sent by GOTOES and GOTOES codes the sport as "21," which corresponds with "eBike"... NOT "Other". So, to clarify, Garmin Connect is incorrectly interpreting your activity as "Other" and as a result, not displaying the Cadence Graph.
Alternatively, you could also change your activity type to cycling or some other activity type before uploading to Garmin Connect if you don't want to make the change in Garmin Connect itself. Meanwhile, I encourage you to
report this bug to Garmin Connect. You may refer them to this thread. You can tell them that files with "Sport" set to "21" and "Sub-Sport" set to "0" are being detected as "Other" when they should be detected as "eBiking." All other platforms such as Strava, intervals.icu, and Training Peaks are interpreting the GOTOES file correctly.

- Correctly Detected in Intervals.ICU
- Screenshot 2025-04-20 at 8.19.03 AM.png (27.99 KiB) Viewed 722 times

- Correctly Detected in Training Peaks.
- Screenshot 2025-04-20 at 8.22.56 AM.png (15.58 KiB) Viewed 722 times

- Correctly Detected in Strava.