Thanks for providing these for me! I can confirm I'm able to replicate the crash with the smaller HEIC file - though it's Affinity at fault and not the file here.
Therefore I'm logging this file as a bug with our developers now, to be fixed in a future version.
In the meantime, you can convert these images to .TIFF, where they can then be used in Affinity without crashing.
I hope this helps