Why is my nelly moser clematis only flowering at the bottom
A mature nelly moser is suddenly only flowering just above ground level. No sign of flowers on upper growth
Certified GKH Gardening Expert
This sounds like a problem with pruning at the wrong time, or not pruning enough.
This article will help: https://www.gardeningknowhow.com/ornamental/vines/clematis/pruning-clematis-vines.htm