What issues did he have with her?
Genuine question: I've just been googling and didn't find anything about that (possibly not using the right search terms?)
Yes, he didn't keep her on - but of course Queen Camilla would have her own household already established, and with the death of ER II there would be no role. She was given a house (hers for life) as part of her exit terms, which is pretty good as part of a redundancy package. And after 30 years service, I'd expect there's a good (public sector) pension too.
KC got a fair amount of bad press about some actions after his accession (such as waiting until Edward's birthday before creating him Duke of Edinburgh) and there was lots of chuntering. And I was wondering if this was just another part of that chuntering, rather than anything amiss. She'd been such a fixture in ER II's life for so long that I'd have thought the others (RF, courtiers, more junior staff) would have just seen her as part of the landscape, and a reliable, trustworthy part to boot.