Congratulation on fixing the issue, your post on J-Link emulator and special connector will be helpful for others in future.
Wait...you have 6 batteries now? The way growatt batteries are being connected in parallel kinda......count as a disaster?
Can you check the amperage of each batteries when they are charging and discharging?
The reason, please watch this video from beginning to the end:
Ideally, you wants each battery pack charge/discharge equally (or close to same value).
Granted that each battery pack will eventually equalise themselves given sufficient time....but.......you gonna have 2 battery pack getting worn out first out of 6 packs total if you use growatt default wiring configuration.