Does anyone have experience with Cellmeter 8 or Cellmeter 7 ??

[Master Yoda]

I am building a small solar system for my shop and have on order from China 4- 200Ah LiFePo4 cells which will be wired in series to yield
12volts DC. I have the solar panels set up along with a MPPT solar controller and a BMS for the battery. As the BMS is a NON-smart version
my thinking was to connect a Cell Meter 8 to the battery and there by have the ability to view the status of each cell.
I just received the Cell Meter 8 and wanted to test it while waiting for the batteries to arrive but there is some sort of issue that I cannot wrap my head
around.
For testing I was using an 18650 battery and when I connected the first line to the battery everything worked well. I then tried the second connector
and it basically would not work and reported the battery basically depleted. This not the case as the battery is fully charged.
When I tested lines 3 and 4 nothing appeared on the screen.

My question is, does this device require all of the connection points to be made simentaniiosly? Is the meter built with the measurements in a series or in a parralel mode?
Just guessing here?

Thanks in advance.