@NotMainstream, Could you please provide screenshots of the following:

1. Apps screen.
2. App selection screen within the VPN profile.
3. Network logs screen.
4. Rethink app version.

Also, does the refresh icon on the app selection screen doesn't help?

I've also noticed this.
Usually when I install a new app, first I gotta refresh the main apps list (in case it wasn't detected/added already), wait about a full minute and then the proxy apps list refresh button will find the new app because refreshing it right away won't do anything even if I spam it, or just show it for a split second then hide it again till I refresh after a minute 🤔

My guess is that RDNS seems to use different app lists for rules and proxies that can desync when packages are added (or removed) so perhaps it should just merge them and use a single list (I'd love to be able too add an app to a proxy via the main app rules menu, but being able to select multiple apps from the proxy's list is also handy).

Also, I think apps that use app lists usually have broadcast receivers to detect package changes like these, which I noticed ReThink doesn't have:
android.intent.action.PACKAGE_ADDED
android.intent.action.PACKAGE_REPLACED
android.intent.action.PACKAGE_REMOVED
android.intent.action.PACKAGE_FULLY_REMOVED

Also, I think apps that use app lists usually have broadcast receivers to detect package changes like these, which I noticed ReThink doesn't have:

We removed listening on those broadcasts because it caused battery drain for reasons that escaped us at the time. While the installed apps list is auto-refreshed every 3 hours, Rethink can also track new app installs "just in time" when a network requests comes in and it couldn't identify which app it was from (most likely means it was a new install).

My guess is that RDNS seems to use different app lists for rules and proxies that can desync when packages are added (or removed)

Yes, the in-memory caches + database tables are separate for firewall rules and proxy mapping rules, but that's more of a sqlite limitation (no "foreign key" support). We could use a singular database table but that is also not without complications. Desync between these tables/caches can happen but "refresh" should fix it.