[Selections from a CMYK document copied to clipboard are very low resolution]

Open/create a document with a good resolution and cymk. 3750x2550px @ 600 dpi in my case. 

create a pixel layer with something on it.

select a portion of the layer and copy it. 

switch to another application and paste.

It looks like a scaled up thumbnail instead of the actual image copied.

pasting within affinity works fine.

both copy and copy merged give the same low res output.