Can’t adjust height on new U36V 46cm HPTM Brushless Lawn Mower?

I just got a 36V 46cm HPTM Brushless Lawn Mower but I cant adjust the height.
 

I’ve read the instruction manual and watched a YouTube video but when I slide the adjusting lever forward and attempt to lift up by the handle it doesn’t adjust the mower height up or down it just stays in the place and the height indicator doesn’t move position either.
 

An additional thing is that it seems the lever is supposed to move back to the position it is in the photo when you release it but on mine it acts more like a switch and doesn’t slide back by itself when you let go.

 

Lever pic

 

Height adjustment indicator:

 

Any ideas on how to fix this or is this a problem that should be addressed by returning under warranty?

Thanks

Damian