Your batteries have started to progressively age and developed cells with high internal resistance.
Those are getting first at the high voltage threshold and trigger the high voltage alarms.
Don’t want to alarm you but slowly, in the future, will also be overvoltage alarms and Pylontech technical department, if you apply for warranty at some point, will want first to see the event logs from batteries and have their eyebrows raised when they’ll see so much high voltage alarms.
For Pylontech batteries, the lowest for 100% SOC is 52.2V, but you already have it at 52V.
You could try to lower it further, to 51.75V, which, after the current is settling down, it’s about 97% SOC.
Don’t worry about balancing, that is starting as soon as one of your cells is over 3.36V and deltaV is above 30mV.
So the packs will balance, even at 51V.
But this is a solution for masking a problem, not solving it.
If you have good technical skills and the batteries are out of warranty, I would sacrifice one battery to take from that good cells with low internal resistance and replace bad cells with high internal resistance from the other ones.
I’ve tried to explain things here: High cell voltage nach Erweiterung der Anlage - #27 by alexpescaru