most trucks these days come with a battery type select in the setup of the software. If these batteries were recently installed maybe they forgot to set the battery type in the truck? So it's reading incorrectly causing the irregular display output? Reflashing the firmware is fine if it actually needed it but even then you would have to go into it and make sure all the settings for the truck are set correctly, generally a flash program is set to standard settings by default and may not be set specifically to your machine's options.
just a thought to consider...
Another thought, if they came with these batteries and everything is setup correctly then there is another issue, possibly a characteristic of these batteries.
How old are they? Remember this is new technology and i'm sure you are aware that they can and will give problems being it is so new. They have great power curves but as with all batteries do get charge sensitive and will start to reflect that in their charge retention and max capacity capability over time.
These new operating systems in these lifts are very voltage sensitive and any variation from what it expects to see can and most likely will have a drastic effect on the performance and operation.