Double-HTML-encoding in the chat window

I was having a conversation about HTML in jitsi meet and we noted that HTML tags get double-encoded in the chat window (i.e. you see the & signs).
Surprisingly this only seems to happen on the instance I maintain and not on various other instances I tested. So I assume I’m doing something different than others. I’m attaching 2 images to show the difference.

My instance runs with the docker installation method and is very close to the original. Anyone any idea what I might be doing differently than those other instances?