I have been using my printer (Flashforge, Creator Pro, Dual Head) occasionally since I bought it in May. In the last few weeks I have been using it more.
Yesterday, when I started trying to print something with the left extruder, it would only print from the right extruder. I don't believe I changed anything in the settings. I have repeatedly tried to print other things, specifying the left extruder, but they all start printing to the left.

I know I could load the filament to the right extruder to resolve this, but I also recently had right extruder issues where the filament does not print well on the right extruder. Which is a separate issue, but also very annoying. The extrusion speed on the right appears to be slower than the left. I have checked the feeder wheels are clean and all appears ok.

Any suggestions on why it would stop printing from the left head?

Thanks

BigKiwi