No, not normal but not unexpected either. April is a bit late in the season to transplant a clematis and the root system is still trying to get used to the shock and re-establish itself. If you had moved the vine in October, you would be seeing a much different reaction.

10" of mulch seems incredibly excessive to me - more usual is 3-4". But keeping it well-watered now and through the rest of the season is key. It should be fine next year.

I couldn't have transplanted it, earlier, as the ground was frozen.

As for the mulch it is just a mound around the base. I think it is more around 5/6 inches, sorry I exaggerated a bit :)

I had the naive idea that maybe the clematis being exposed to little sun the past 4 years, has a hard time to re-adjust to the sun, combined with the transplant shock.

Is there any truth to this theory?

I couldn't have transplanted it, earlier, as the ground was frozen.

As for the mulch it is just a mound around the base. I think it is more around 5/6 inches, sorry I exaggerated a bit :)

I had the naive idea that maybe the clematis being exposed to little sun the past 4 years, has a hard time to re-adjust to the sun, combined with the transplant shock.

Is there any truth to this theory?

Maybe 95% transplant shock, 5% change of exposure :-)

Thanks :)