Some leaf loss on evergreens is normal, but if you have excessive loss, that's clearly not. Where's it growing, pot or ground, and how long have you had it?

It has been in the ground for about 4 years. Not lots of leaves but it seems to be a few every day with a mottled appearance.

I don't know what your weather's been like up there, but down here its very, very dry, so check whether that's a problem. Otherwise, give it a good feed with a general purpose product (Growmore or Vitax Q4) by forking it around the base. Cut back any obviously damaged or unhealthy growth. Check the stems and branches for scale insect or other infestation.

Yes, my photinias drop leaves like mad when they're too dry.
If i water them when we have a dry spring (like this one) they don't lose half as many.

That's normal with photinias....well it's normal with mine each year but its no big problem and they continue to do well . Give it a good soak at regular intervals.