Steps to reproduce:
The first issue is that in Discourse, when you highlight some text in a post, a little pop-up is supposed to appear to allow you to quote that text in a reply, like this (from Firefox):

In Orion, however, the selection is unexpectedly expanded and the pop-up doesn’t appear:

I have also tested this in Safari (Version 15.5 (17613.2.7.1.8)) and it works as expected (i.e. like Firefox) in that browser.
Expected behavior:
The selected text should not be expanded beyond the highlighted text, and the pop-up controls for Quote and Edit should remain visible.
Orion, OS version; hardware type:
I’m running macOS 12.4 on a 2021 MacBook Pro 14” with M1 Pro CPU. I’m using Orion Version 0.99.115-beta (WebKit 614.1.12).
(I was also asked to mention that I am an Orion+ member.)