uke

Could it have been Eq, i.e. the lower segment of the "9" wasn't on, hence this was a "q"? 
Does your model have equalisation facilities? For example, can setting 26 (bulk/absorb voltage) go past 58.4 V to 64 V?

You usually don't want equalisation with an LFP (LiFePO₄) battery, such as a PylonTech. That's part of the reason for the Eq sign, it's a warning that something potentially dangerous is happening.

The battery is considered low when it's 2.0 V or less over the battery low DC cutoff voltage (setting 29). This isn't documented anywhere that I'm aware of. It doesn't lose its "low battery" status until the battery voltage rises 4.0 V above setting 29. (The 2.0 V becomes 0.5 V in the LFP flavour of the patched firmwares, and the 4.0 V becomes 1.0 V. )
So try reducing setting 29 by a volt or two.
See also FAQ #1 here.

Remember, it's "Eq" not "E9". It's difficult to be clear when using seven segments for letters.
I would make it 45.5 V, so that you don't switch to utility earlier than what setting 12 dictates. This is mainly for 04 warnings, not errors.
That's a Good Thing™, unless you have flooded lead acid batteries that require the very high equalisation voltage. The 1:7 transformer ratio in the 64 V models means that clipping of the output starts occurring at about 47.9 V in the 64 V models.
Interesting that you have a non-64 V model, yet with equalisation in the firmware. Did it come from the factory with the firmware you are running now? My apologies if this was already posted.