Insufficient space for iMovie export on iPhone 13 Pro

Hello,

Lately I seem to be having issues with trying to export a film from iMovie on the iPhone 13 pro. It stated that there is insufficient space left. I'm trying to export a stitched together film consisting of 14,8 GB. However, the error message states that there is only 9,6 GB available. The export settings are in 4K, 60 fps.

I'm trying to create a video from 4 individually recorded videos, taken with the app 'Filmic Pro' and stored in 'Photos'.

• I have used 56,8 GB of storage of 128 GB in total
• I have the film stored locally in iMovie now and deleted the 4 individual videos from 'Photos'
• Even though I assume it shouldn't matter, I have used up 400 GB of the total 2 TB icloud storage

This has been going on for quite some time. I ran into this problem with the iPhone XS as well, even though that phone had only 64 GB of storage. I assumed it had to do with the limited storage. Now I have double the storage and it still is giving me this error.

When I archive some apps, I will get more 'free space' and the iMovie error will reflect as to having a bit more space, but I cannot overcome this difference with just deleting apps.

Also, all my photos and videos are stored in iCloud, why is it then taking up 17 GB of space locally. Thumbnails and such? Seems a bit too much. I've been a fan of iPhone for a long time, but they handle storage awfully.

Am I running into a bug? This is very annoying!