After a few sleepless nights
, I finally managed to get the application working with interrupts 
I created a virtual APP IVT, and now all the jumps are correct. My biggest problem was that the APP IVT isn’t located before the program code, but rather in the middle of it. I first had to define a section starting at address 0x2000 (which only contains the jump to the actual application, which begins at 0x2400, i.e., after the APP IVT).The link you shared really helped me understand the concept of the virtual APP IVT. Many thanks for your support and the thought-provoking guidance
Best regards
Daniel