When I adjust my level of perceived effort on the Garmin Connect site after a ride there is something odd with the sliding selector.
This is the same, be it on Firefox or Edge browsers (both updated to their latest versions)
As you can see from the attached image, when I move the slider, it gets to what I'd expect to be the 1st tick box, but it's already on Maximum...and the increments are tiny
I could add the remaining 7 screenshots, but I think this puts the point across.
Something must have changed recently, as this wasn't the case going back a few weeks when I was able to slide the selector to the far right