iPhone won’t stream properly with Apple hdmi adapter 2 tvs, two iPhones and two different adapters

Hi 57ginger,

Welcome and thank you for posting in Apple Support Communities.

If we understand, the video lags regardless of which iPhone you connect to either of your TV's using an HDMI adapter. Swapping those around, trying different combinations was really good troubleshooting. We appreciate you letting us know.

Did you try different HDMI cables? That's one thing that wasn't mentioned. Also, the adapters are compatible with TV's up to 1080p HD.

Did you switch to the correct video source on the monitor, TV, or projector? See Connect iPhone to a display with a cable for details.

Take care!

Salutations 57ginger, 

The latest version of iOS is 16.3.1. Please create a current backup and install that update on your iPhone 12. Also, make sure any there devices involved are up to date. 

How to back up your iPhone, iPad, and iPod touch This article includes steps for backing up to iCloud, a Mac or a PC. Just choose which method you prefer for the step by step directions.

Update your iPhone or iPad

Update your iPhone or iPad wirelessly

1. Back up your device using iCloud or your computer.

2. Plug your device into power and connect to the internet with Wi-Fi.

3. Go to Settings > General, then tap Software Update.

4. If you see more than one software update option available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

Thanks.