Parameters won't save and other odd behaviour

Paramters on Pixhawk have reverted back to what seem to be default values and when I change them back to my desired values (in mission planner), they won’t save but revert back to default values when I refresh. Also getting gyros inconsistent fault which won’t let me arm.

It all started happening quite suddenly.

I’ve done and double checked accelerometer calibration.

GPS is glitchy but no particularly so, I’m not currently in an open space so it is to be expected I think.

I haven’t tried re-flashing yet.

Is the flight controller likely gone?

Pixhawk 2.4.8.

flash with latest stable for Pixhawk1