When you look at your video, you see that quickly before you acknowledge the second Vorsignal, the 1000Hz light goes off?
Really man, you release an austrian loco and you don't know the OEBB Signals? (just joking)
EDIT: Now I see, yes. I placed an 1000hz Perm. and now it's working but the 1000hz dissapears when it receives a new Beeinflussung? It should stay blinking !