All I can tell you is that this is the link I ordered "https://www.fasttech.com/p/3864308" what I got was actually labeled 40C. Never tried to test the actual C rating, I was just happy with the battery analyzer results. Measurements on the SS were taken by myself and dont match the website listing. I chalked it up to "they screwed up".
Whenever that has happened to me I usually find that there is a problem with my coil. Check your cold-ohms while you are getting devil-butt, if they are higher than normal either work on the coil or lock ohms at the normal value.
It might be good to make a footnote about this in the Datasheet. Several people have had similar panic moments expecting the screen to light up like the DNA200 did.
Please post a screen shot of Device Manager after you take a hit that gives the weak bat message. In many cases it because of voltage drop. There is so much voltage drop during the preheat that it triggers the message, but once preheat is over you most often find you had enough voltage to satisfy your temperature requirement for the hit. In other words, it may not be worth worrying about. Device Manager will tell us
Look at your cell #3. Unplug the battery, or at least the JST connector and manually measure the cells. If cell #3 is truly 0.8v then replace the battery. If cell #3 is more/less normal then RMA the board. While battery is out check the fuse. I hade one very similar, and the battery worked in another mod just fine. Mine looked like this and fuse was good, I RMAd the bard.
If all else fails, and you are concerned about the accuracy, run the Battery Analyzer on your mod. It will be dead nuts on the money after that. Its not uncommon for mass produced Lipos to vary in capacity, even within the same lot.