Kuhn mowers have removable shield plates right where you have the blades grazing the mower. I had similar issue last year but after 20 euro and couple hour repair it was like new.
How have you got the back mower to that joystick? Have got front and back for an N174 and it’s just a slut having to yank the stick then yank the spool
If you’ve got factory fitted front linkage and front loader with the electric changeover between them you will have a 3rd mid mount spool but it won’t be piped to anything I just ran pipes from that to the backend