Collapse Chat button not showing.
The collapse-Chat-Button is not visible on the Squad-Stream page.
It seems like, you have a Order Problem. The Button:
<div class="Layout-sc-nxg1ff-0 eDtWqr multi-stream-player-layout__chat-toggle">...</div>
is above the Chat divs, which mean they are displayed over the button, due to all of them having the same z-index. Resulting in a not visible Button.
Browser: Chrome 101.0.4951.67 & Firefox 100.0