HEIC/HEIF lossless implementation doesn't work
GIMP version: 2.10.8
Operating System: Windows 10 Home [64bit]
Package: Installer from gimp.org
HEIC/HEIF lossless implementation doesn't work
Reproduction: Always
Reproduction steps: Not needed
Expected result: Lossless RGB Image
Actual result: Lossy image without warning. Probably YUV image.