Hi @ahargreaves_FW
(just reread your post, and realized i misread. So updated answer below, i deleted my first response)
It is expected that the Production URL is still included in the list portals that you see when you manually tap to sign into Field Maps. This list is actually a "recent portals" list, not a "potential portals Field Maps can access" list - so it will continue to show the Production portal URL as it is a portal that has been signed into successfully.
Noting, however, that when the portalURL value is set, when the app is launched the user should be brought right to the sign-in screen for the portal so they shouldn’t see that list when they launch fresh. That list would only be shown if they sign out of the Stage portal, and then manually sign in again without killing/relaunching. As if you kill/relaunch FMs it would take them automatically to the portal specified in the portalURL.
If you did want to clear this list - you could uninstall/reinstall to clear this out.
Hope this clarifies. Let me know if further questions.
Thanks,
Heather
