Light Probe Proxy Volume and Batching

I'm curious why do LPPV break batching? let's say i have a scenario where an entire room have one big LPPV object and all object inside that room are refer to that LPPV object, by that everyting should use that LPPV already but in Frame debugger i still get a message Object can be batched because it's affected by different light probes.
i understand if i use lightprobes but since i use LPPV how come it still break batching?