Fendt 820 rear linkage lowering

[Farmer mk1]

Evening
The 820 we have had a problem when we are mowing with the front and rear mowers. The rear mower lowers down when I think you press the spool to float the mower down or press the spool to float the front mower. It seems to be worse when it is warm. Has anyone had this before on the fendts?
Thanks

 

[AdamHoggard]

Is it the blue spool that you're operating?

 

[Farmer mk1]

It can be the red or green when operating the mower. The blue or yellow is in float constantly

 

[AdamHoggard]

It can be the red or green when operating the mower. The blue or yellow is in float constantly

Keep blue out of float and see if the rear links fall