Just tried scanning the QR code shown on my local Emoncms instance using the Emoncms app and it worked perfectly from what I can tell.
That’s with a Pixel 2 running PQ3A.190801.002, Emoncms app 2.3.0 and Emoncms low-write 10.1.3.
Let me know if there is a specific QR etc you’d like me to try 
