Dynamic changes don't play out

Hello I have a bit of a conundrum.
As shown in the screenshot, the crescendo I put in Pno. 1 bar 8 does not play out, as long as I put the pp (or any other dynamic) in bar 9. When I don't change the dynamic in bar 9, the crescendo plays out perfectly fine.
Is that an error or is there a way to change it?
The dynamics are assigned to the stave, it doesn't matter if I use < or cresc._ _ to represent the change in dynamics or if I assign all dynamics to the part, the stave, the System...

Greetings!