Q.What Is This ‘tree’ Growing With My Dwarf Lilac Palibin?
I planted a dwarf lilac palibin a few years back and the last couple of year another type of what looks like a tree has started growing with it. the leaves are a lot bigger so don’t think it is the same type. there are no other trees nearby

Certified GKH Gardening Expert
Unfortunately, I can't get a good look at the specimen. It does seem that, maybe, a hackberry has grown with your shrub. I would recommend cutting that out, and keeping it cut to kill it off.
This collection of articles will help you with your original shrub: