Python Node Development - Icons not visible after bundling

Hello KNIMErs,

after successfully bundling my nodes I wanted to test them locally.

I am able to see my nodes in the repository.

However my Icons are not visible anymore.

Please let me know what I should provide to investigate this further.

Maybe @AD1529 / @Daniela_Rotelli has experienced a similiar issue before?

Note: Extension is written in Python.