Hi, some thoughts:
D8 blinks few times a second
This normally happens when the power adapter is not delivering enough current to Reform. It is advised to use a stronger power supply.
D8 is on while D9 is blinking once every few seconds (few seconds on, few seconds off).
This sounds normal, it should be the balancing behavior. Charging is turned off during balancing (when discharging overvolted cells).
D9 will go on when the LPC firmware turns off charging, see:
When I turn on laptop after longer period of it being turned off (longer than 2-3h) OLED shows ???.
I also have this recently. I would like to fix it, but didn’t have the time yet due to a perfect storm here of a lot of new products/batches being readied for testing and shipment.
I suspect it is the brownout reset being a bit overzealous. I activated it in a relatively recent version of LPC firmware to make sure the LPC never crashes/freezes/is able to recover from undervoltage crashes. Perhaps one can tweak its sensitivity. See the LPC11U24 reference manual.
See also:
LPC11U24 manual: