So just returned from a skiing holiday in Austria. Used my spark a couple of times with the remote but the next day it unlinked and won't relink ( I just get the usual annoying beep and flashy red light). Tried all the usual linking procedures including resetting the drone and RC with a 9 second press and also tried some things suggested on YouTube but to no avail. This happened once before a few months ago a few days before a firmware update but the update seemed to cure it. I can link the phone to the controller no problem and the go app seems to think all is well and lets me go fly but the controller flashes red and beeps and doesn't work. I can fly with the phone but prefer not too. Any ideas?

Sir, please ensure that the firmware of your RC is the latest one. Did you try to flash the firmware with DJI Assistant 2? Please keep us updated, thanks.