pkhex legality Zygarde from Y with Ribbons becomes Illegal when given Power Construct via Route 16 Reassembly Unit in Sun

[MrMadness]

As the title says, my Zygarde from Y with Ribbons from Y and Alpha Sapphire becomes Illegal when given Power Construct via Route 16 Reassembly Unit in Sun. Anyone knows why it became illegal despite the fact that it's legitimately and legally obtained?

 

Zygarde's PKHeX File: 718-03 - Zygarde - 4EE0CB6BDAF7.pk7

[Atrius97]

This appears to be a bug in the program, I've submitted a github issue on your behalf.
https://github.com/kwsch/PKHeX/issues/3834