How can IRemove Unknown managed networks from my iPhone 16 pro max

This is a stressful situation, and it is completely understandable that you are feeling on edge given the persistence of these settings. The good news is that on an iPhone 16 Pro Max, Apple makes it very transparent if your device is actually being controlled by someone else. Your first and most important step is to check for "Mobile Device Management" (MDM), which is the specific software companies (or bad actors) use to control phones. Go to Settings, tap General, and scroll down to VPN & Device Management. If this section says "No Profiles Installed" or simply shows a VPN option, your phone is not under remote control, and you are safe from that specific type of takeover. If you do see a profile listed there that you didn't install, you should tap on it and select "Remove Profile" immediately, which will require your iPhone passcode to verify.

Regarding the "Managed Networks" you cannot delete or see passwords for, these are most often harmless "Carrier Hotspots" rather than malicious spyware. Carriers like Verizon, T-Mobile, and AT&T program your SIM card or eSIM to automatically recognize their public Wi-Fi networks (such as "Xfinity Mobile," "AT&T Passpoint," or generic names like "CableWiFi"). Because you transferred your phone number to your new iPhone, these network rules transferred along with it. While you often cannot delete them entirely because they are hard-coded into your cellular settings, you can stop your phone from using them. Go to Settings > Wi-Fi, tap Edit in the top right, find the network in question, tap the "i" icon, and turn Auto-Join to OFF.

For additional peace of mind, you should use the "Safety Check" feature designed specifically for people worried about unauthorized access by someone close to them. Navigate to Settings > Privacy & Security > Safety Check and select Manage Sharing & Access. This tool will walk you through exactly who has access to your location, photos, and data, allowing you to revoke permissions instantly. If you still see strange networks that are not carrier-related, you can perform a "clean slate" flush by going to Settings > General > Transfer or Reset iPhone > Reset and choosing Reset Network Settings. This will delete all saved Wi-Fi passwords (including your home one) and clear out any lingering "ghost" networks, forcing the phone to start fresh with connections.

Where are you seeing them? If they are at Settings > WiFi > Edit, then these are the ones provided by your cell provider. You can contact them and see if they will remove them, but honestly I have never seen where they would do it. That would leave you with the only option to change cell providers and of course you would have to find one that does not include those Managed WiFi networks.

Managed Wifi Networks are provided by your cell service. They are not using MDM or have access to your device at all to be a risk to any of your personal data. Removing the SIM of the cell provider will immediately remove any of those Managed WiFi networks. I don't know of any cell provider that does not have at least 1 managed WiFi network. If you use T-Mobile you have 2 of them and the one called Tmobile Wingman is used for free WiFi access on participating airlines. Others, such as Verizon include free WiFi access at major sports stadiums.

Remove any remembered networks

Step 1 — Go to:

Settings → Wi-Fi

Step 2 — Tap the “i” button next to the network

(If the network is not currently in range, it does NOT appear — this is normal.)

Step 3 — Tap Forget This Network

If you cannot forget the network, it means:

• The network is not actually known — it’s only being shown because it is nearby, or
• You have Private Wi-Fi Address enabled, so the system generates unique addresses per network, or
• You are not connected to the network (iOS only lets you “forget” networks you have joined before).

You cannot forget a network you have never joined.

This is normal behavior, not evidence of control.