This is Hot Start MIG 21!
As you see, NPP glide slope remains focused like this, and no matter what I do (I don't use SAU I land manually according to PMRG glide slope) but now I can't use it since it remains fixed ALWAYS (+) like on this picture.
As I remember, Mig 21 hotstart shouldn't have NPP glide slope focused.
Is your situation the same?
I tried few airfield approaches with correct setup it remains fixed.
Of course I have RSBN navigation ON and PMRG (Down) when approaching.