I understand the problem now.
PPL_B gets its own copy of "Get Tag LUT.vi" when you compile the PPL.
Then when you call VI_A, it refers to the "Get Tag LUT.vi" in vi.lib.
They are not getting the same tag lookup table.
To avoid this, I think that you will need to build Get Tag LUT into its own PPL. Then have PPL_B and VI_A call that PPL instead of vi.lib.
This would requires some re-structuring of the Tag Engine library before building the shared PPL.