Static Batching issue in ver 5.4.1

I am using ‘Highlighting System’ asset.(Unity Asset Store - The Best Assets for Game Making)

After version update 5.3.2 to 5.4.1, i have some problem.

When ‘Static Batching’ in ‘PlayerSettings’ is checked, ‘Highlighting System’ combines wrong static meshes.(It’s nice worked in 5.3.2)

What is happened and changed in ver 5.4?

I’ve never used the asset, but a cursory search of its support forum suggests this is a known issue: you either need to downgrade to 5.3 or set outline iterations to 1.