Ele and ail channel output always Min or Max

After configuring my APM 2.6 board with the Plane firmware (It previously had copter firmware installed) whenever I choose any flight mode other than manual the output of channes 1 and 2 alternate between Min and Max.

I’ve reset the board and gone through the setup process a couple of times but I keep getting the same behaviour. The accelerometers work fine and the readings are correct, and when moving the plane both ailerons and elevator move in the correct direction (trying to bring the plane level), but always at min/max output.

Any clues what might be wrong?

Best regards.

Here is a screenshot of channel 1 Output so you can clearly see what the behaviour is.

Best regards.

The most likely reason is that the P gain on the roll controller is way too high. If you post a tlog it would be much easier to find the issue

Pgain is default for both pith and roll (0.400). Tlog attached.

Best regards.