This may be an issue with Kakoune or with kak-lsp. I don’t really know and I’m not sure what I could provide more information on this issue.
On writing certain filetypes, Kakoune ends up hanging on waiting for shell command to finsih.
This was posted on the Kakoune subreddit.
EDIT: According to someone on the Reddit post, this is an issue with kak-lsp. If you kill all instances of kak-lsp you get Kakoune back from the infinite waiting for shell command to finish.
I’ll get all of this on an issue on the kak-lsp project page.