I have a 2019 P800 which I tested with OEM inks and worked well.
I have replaced these inks with new filled Piezo cartridges, and installed the decoder board for the P800.
I followed the written instructions and also the video to the letter, and double checked all positions, rebooted the machine etc.
I receive an error message on the printer that ALL of the cartridges are not installed correctly.
It could be the decoder board, but I installed it exactly as the instructions.
I have not done a reset on the decoder board - the instructions say that the printer should recognize the inks as 100% full on the first install.