Cotoneaster Dammeri Yellowing Foliage

[MattATK03]

I recently got this cotoneaster a couple weeks ago.
I’m in zone 9 and after it arrived I noticed the patches of leaves starting to yellow.

It was in a much smaller pot and I slip potted it into this slightly bigger one with more soil. I had suspected it might be overwatering so I’ve been watering less frequently, about every 2-3 days, but more leaves are yellowing and some turning brown.

I’m not sure if this is natural due to fall or there is something else going on.

Any tips are appreciated!
Thanks.

 

[Rivian]

Its gonna die, Im calling it. Looks like the branches are drying up, look at the wrinkles in the bark

 

[Shibui]

It does not look good to me either. I think it is worth contacting the seller to see if they have a replacement policy. C. damerii should be evergreen so yellow leaves any time of year is not good.
Slip potting is not always the best option. The difference between new and old is sometimes too much for water to pass through so existing roots can stay too wet or too dry despite the new outer soil being OK.
You have not specified whether it is kept inside or outdoors but regardless it should not decline this quick due to location.
Over water could be a possibility but I think under watering either before, during or after shipping is far more likely.
It is worth keeping up care for a while longer. I have seen trees come back from looking really bad but I'm not optimistic about this one.