theres is a pretty flat energy curve with lithium so the old fashioned lead acid volt battery gauges dont really work very well until its really dead.
Also, the 3.2v in those batteries are 3.650v fully charged and like 3.1-3.2v when down to 20% which is about as low as you want to go with lifepo4 batteries without damging thier life expectancy... Since theres 4 cells in a 12 lifepo4 battery that means the battery still puts out about 12.8v when essentually fully discharged at the safe max. And the pack still puts out over 50v which is higher than the peak of the old 48v battery meter... in short you need a higher voltage battery meter preferably something like a digital meter. a digital volt meter or a programmable volt meter like this one im using now with my old batteries
https://www.ebay.com/itm/265643697888?var=565431890126
works well.