I got lost somewhere. ISTR Battle Born says theirs quits if it sees 14.7v, but yours shuts down at 15.6v? Battle Born says it needs to see 14.1 to get the balancing started, but I don't know what it balances to.
It is supposed to be to some voltage that the cell that gets there first is limited to while the other three catch up.
If that is as high as the first cell gets, then how can the average voltage of all four get any higher, so why the high voltage shut off? So if the BMS goes bust, and the cells just keep on climbing in voltage it shuts down? But what shuts it down since the BMS is broken in this case?
Anyway you don't have a Battle Born so you don't care :)
I remember when I was learning solar I had the voltage get over 15v and the inverter quit at that voltage. So I wanted to knock the voltage down, but the inverter wouldn't work to do that. I got it all working eventually. I am thinking if the Li shut off until it got down to the restart voltage, you might have to run around trying to knock its voltage down, but how? since it has shut down! Hmmmm.