Firstly, Pear is very difficult from cuttings. Leaves will often sprout on cuttings, just as if you had put the branches in a vase of water. But leaves opening does not imply that roots are forming. When the leaves have exhausted the energy in the branch the leaves will die. Without roots they can't replace it. Even easy woody subjects don't root in a week.

There can be various reasons........wrong time of year for the cutting, incorrect preparation of the cutting, lack of appropriate aftercare. And the difficulty in striking cuttings from that specific type of plant. But very likely, the roots have not yet developed sufficiently to support the any foliage growth, which was growing from the previous season's reserves.

I wouldn't necessarily give up hope yet. A 'few weeks' is often not enough time for the roots to develop well.

And if you do not succeed this time, spend some time researching the best methods for propagating by cuttings the plants you wish. The requirements will vary. And always take twice as many cuttings as you think you will need or want. The success rate is usually low :-)

My success rate is almost zero.