Stihl Leaf Blower Vacuum BG 56 C-E Has very low duck/blow?

I have an almost new Stihl BG 56 C-E. I used it the day I bought it and it worked perfectly.

I've used it again today and it had almost no suction. The engine is running well, and all the troubleshooting instructions relate to the cause being lack of engine power - which is not a problem in this case.

I'm not sure if the air flow mechanism could be blocked somehow while the engine runs at full speed?

I've tried it in both blow and suck modes and the problem is the same.

Any suggestions?