[IDML import not working - Affinity gets stuck/frozen]

Hey, if I want to import IDML into Affinity Publisher, everything (Affinity Publisher) gets stuck/frozen. That's really sad and unfortunate for me, because I've got continuous projects from InDesign, with which I want to continue working in Publisher. So it's not possible right now. Is that a common issue? Furthermore, while importing into Affinity, it's taking up everything I have on free space on my MacBook until there are no Megabytes left, no storage capacity anymore. The IDML projects are quite big, but not that gigantic and work perfectly fine (without that need of space) within InDesign. I tried several times with big and small IDML files.

Thank you, if you can help or rework the IDML import