For comparison Using the same charger with my nexus 5 my phone would stay connected even at full capacity (I'm sure it has a internal safeguard for overcharging rather than disconnecting continuously)
I'm using one of those aftermarket qi wireless charging stickers.
(edit) I ended up buying a OEM LG battery door with qi built in. I get the same result. It's the phone.
Anyone else experience this or have a solution?