Element does not interpret markdown after first encountering a room pill

[ShadowJonathan]

Steps to reproduce

Trying to send the following message;

Results in the following message;

Source

{
  "type": "m.room.message",
  "content": {
    "msgtype": "m.text",
    "body": "#matrix-spec:matrix.org a *thing*",
    "format": "org.matrix.custom.html",
    "formatted_body": "<a href=\"https://matrix.to/#/#matrix-spec:matrix.org\">#matrix-spec:matrix.org</a> a _thing_"
  }
}

Outcome

What did you expect?

Markdown to get interpreted correctly

What happened instead?

Markdown somehow got interpreted from HTML back to Markdown

Operating system

PopOS Linux, 21.04

Application version

Element version: 1.9.8 Olm version: 3.2.8

How did you install the app?

Flatpak

Homeserver

jboi.nl

Will you send logs?

No

[UwUnyaa]

I just managed to reproduce this with element web (running as element desktop) 1.9.8-1 on Arch.

[UwUnyaa]

Looking through code, I found a reference to this issue: #16660

[SimonBrandner]

I don't think I can repro on develop.element.io

[ShadowJonathan]

I can reproduce it still on develop:

pill_repro-2022-01-15_13.54.50.mp4

[UwUnyaa]

@SimonBrandner the ability to complete rooms in a given room is flaky, so for some reason this cannot be reproduced in every room, and doesn't seem to work at all in DMs.

[robintown]

Probably a duplicate of #20091, since pills are actually links.

[ShadowJonathan]

Indeed

Duplicate of #20091

[UwUnyaa]

This would make sense, as mentions of users are considered to be pills, but don't cause the problem. It suggests that the problem is caused by something else entirely.