Android
Set Default Browser App auf Android
Android allows several browser apps to sit installed side by side, so having Chrome, Firefox, Opera and Brave on one phone at once is normal. Only one of them can hold the default browser role at any time, and that role decides which app opens whenever you tap a link outside a browser itself - inside messages, emails, or other apps.
This assignment is managed centrally in the app settings, not inside each browser. If links keep opening in an app you no longer want, the system simply never received the instruction to switch. Changing it does not touch bookmarks, saved passwords, or browsing history in the other apps - it only changes which app catches the link.
To update it, go to Settings ➔ Apps ➔ Default apps ➔ Browser app and pick the app you want under Default browser app. If the browser you expect is missing from the list, open it at least once first so Android can register it as an available handler.
Switching the default browser never uninstalls or disables the other apps. It only redirects future link taps, and you can still open any installed browser manually whenever you need it.