My clematis never does very well. (2 yrs old) It's on the West facing

Clematis can take several years to reach maturity and that length of time depends on the age of the plant when it is planted. Above ground growth the first year is usually pathetic while most of the growth is taking place under ground. A good root system is critical for a vigorous vine. The second year will result in a larger vine, and the third year will be larger yet. Be sure to fertilize and water your clematis as they require lots of each. This will create a strong root system and a good foundation for years of beautiful blooms. Tomato fertilizer, rose food, 5-10-10, or even an Osmocote type fertilizer are good choices. Slow release fertilizers are preferred.

I have several clematis vines and they usually are an easy plant. One thing I swear by is their roots love shade and the vine loves sun. Heavy mulch works for the ones I have planted in the sun, my others are under trees.

Plant a shrub in front of it, to keep its toots cooler.

https://www.gardeningknowhow.com/ornamental/vines/clematis/growing-clematis.htm

Mulch the plants with compost, homemade if you have it, and then mulch with something like a cedar mulch. They like cool roots with lots of moisture. Do not let them dry out in the hot weather. Water the base, but not when the sun is beating down.

I have some light rocks angled over roots.

Check your soil ph levels to ensure your clematis is getting the nutrients it needs to be HAPPY. :)