Pasting multi-codepoint glyph breaks it into two

Hi all,

When I paste a multi-codepoint glyph (or insert it via an input method), it
gets broken up into multiple glyphs.

Here is a reproduction example. To execute these, you need to ensure proper
unicode support on your terminal (I'm using foot).

Executing the following properly prints a pirate flag emoji (🏴‍☠):

    printf "\U1f3f4\u200d\u2620\n"

But if I copy-paste that same glyph into my shell, I get:

    🏴<200d>☠

However, if I run `cat -`, and paste the same value, cat properly prints back
the multi-codepoint glyph (the pirate flag in this case).

This happens only for some distinct emoji. E.g.: "man shrugging": 🤷‍♂️.

I have ruled out terminal support too (e.g.: as in the above example using
`cat`). I also cannot reproduce the issue when using bash on the same setup.

Have I stumbled upon a bug?

-- 
Hugo