How are you editing the profile? With the databrowser or a different app? If the databrowser, it is probably a bug. If a different app, then you need to authorize the app. In the latest Solid Server BOTH user and app must be authorized and a 403 “origin unauthorized” means the origin of the app is unauthorized. To authorize an app, go to your webId in the databrowser (go to …#me, not just …/profile/card), wave your mouse till the menu appears and select the A. This will popup a dialog to set origin authorizations. Use the protocol + domain but no path i.e https://example.com (no trailing slash)
Go to your profile and open Trusted Applications pane, it’s icon looks like an A.
Side note: this will be more accessible in the upcoming data browser - you can try it out at https://dev.inrupt.net. Try logging in to a Pod there (e.g. https://megoth.dev.inrupt.net) and you can access it through the user menu on the upper right corner, it’s under “Trusted apps”.