Steps to reproduce:
Removed all Orion history, cache, data and app, installed latest version. See code below: and click on the text box, then instead of being able to type text, the page will reload, the behaviour is the same in Gmail (as it use 'contenteditable=true' in reply message box) when you click to reply to a message or click new message then click in the message field, the page will reload. But if you change 'contenteditable=true' by 'contenteditable=plaintext-only' it works right (no page reload).
Tested with all Compatibility mode and possible options and Private mode. No problem in Safari or Firefox.
Expected behavior:
The expected behaviour is to be able to input text.
Orion, OS version; hardware type:
Orion 0.99.115-beta (WebKit 614.1.12), macOS Mojave 10.14.6 (18G103), macBook Air 13" 2015