Messages delete anything that looks like an html tag, sometimes taking whole sentences with it

how to reproduce:

1. send qa5 i <3 you, 2<3 and 5>4, a <tag> here, Vec<String>, `

2. send qa11 if x <y then z, see <https://example.com> and email <me@example.com>

3. reload the page (or look at it from another account).