@florange, can we walk through what happens to dormants in your garden?
When do they arrive?
After they arrive presumably they grow a crop of new leaves - what happens to those leaves? When do the leaves die? What happens to the plants after their first set of leaves dies? What happens to them during the summer and autumn? How does their growth compare that first year to other new plants that have arrived in your garden and are not registered dormants?
What happens to them during the winter? If they survive their first winter and sprout what does that new crop of leaves look like? How does it grow?
Do both you and your friend treat the foliage of your daylilies in the same way - you both remove dead leaves or you both leave them? Do you both weed equally often; do you both mulch in the same way or neither of you mulch, etc.