HV Heavy shild generator stay in ungrouped on pressing autogroup button in Devices menu of Hover Vessel.
I think missing "Ref: ShieldGeneratorBA" in BlocksConfig.ecf cause this to happen.

Also both HV and SV heavy shiled generators missing icons in device menu of vessels.

UPD.
For icons you need to copy and rename ShieldGeneratorT2.png from folder Content\Bundles\ItemIcons. First copy to ShieldGeneratorHVT2.png. And second copy to ShieldGeneratorSVT2.png.
After this I started to see icons in P menu.