Yes, LOTG state that the shinguards must be covered at all times.
The 3rd point from LOTG is laughable as most players want the smallest possible shinguards and look like they borrowed their 7yr olds shinguards. No wonder they roll around on the ground after each tackle.
Why do they prefer smaller shin pads? I remember the ones I used in school, they were huge. They went around the ankle and all sorts. I thought they were class. They looked bullet proof tbh.