Amazon seller app not working on iPhone

For some reason my seller app on my iPhone is not working as soon as I try to list a product it just get stuck on the loading page then nothing need help as I’ve contacted amazon and they said every thing is fine there end delete the app wait 24 hours ???
As was still in sync with the apple update.
But I’ve got the app on my old iPhone and was working fine but since the app updated same issue really need help guys