analogRead using Tinker reads 300-350 second read

Firstly I though my Particle was unable to read analog values at all.
No matter what input it read 300-350 all pins (a).
Then I wired them all to gnd and it read <7 on all.
Connected to 3v3 and they all read > 4080.
With a bit more testing I found that reading the same pin twice would leave the value at 300-350, but if I read a different pin first, then it was fine.

So read a0 and get a good value, and then read a0 again - gives a bad 300-350 value. Continue to read a0, value varies but is still wrong and between 300-350.

But read a0 and get a good value, then read a1 (get a good value), read a0 and get a good value. Always works.

Am I missing something. Do I have to read different pins each time. (I know frequent polling is bad).

Just though this may help anyone else who thinks their analog read is broken.

Which Particle device are you testing on - Core or Photon?

Photon. Just got it the other day :slight_smile:
Happy I can work around the problem, but not sure if there is something I’m doing wrong