Call park range for Site 1 was overlapping with Site 3’s phone extension range (500X)
To make Call park work in this scenario, in Site1’s and Site2’s calling search spaces, you have to order Site 3 Phone’s partition above Call park partitions for Site 1 and Site 2 respectively.
Call park for Site 1 — 500X — Partition – Site1_park
Call park for Site 2 — 600X — Partition – Site2_park
Site 1’s CSS -> Site1CSS —> Site3_Phones, Site1_Park
Site 2’s CSS -> Site2CSS—-> Doesnt matter which way you order this, since Site2’s park range does not overlap with Site3’s extensions.
Rule of thumb, order partitions in such a way that if there is an overlap in directory numbers or patterns, put the more specific match (partition) in the top (in CSS).