On MacOS 26 Beta (I am on the latest release) when I set Orion as the default browser and then click on links in other apps (ChatGPT, Mail, Outlook, Word, etc) it opens a chromeless temporary webviewer pop-up.
To make sure this wasn't an artifact of the beta nature of the OS, I changed my default to Safari, Mulvad Browser, and Chrome. in all cases they opened to the expected browser set as default as expected.
When I click a web link in an application I expect it to open in the default browser, in this case, Orion..
Version 0.99.135.0.1-beta, Mac 26.0 (Build 25A5346a)
Tahoe (26)