iPad os update 17.4 breaks external monitor support..AGAIN!

Having tested a fifth generation iPad Pro 12.9" updated to iPadOS 17.4, I can confirm that Stage Manager/Screen Mirroring with a connected external display is not operating as expected.

While the iPad screen will successfully mirror its screen to the external HDMI display, full screen (Stage Manager) is not enabled as expected when disabling Mirroring from the screen Arrangement settings.

I have verified this behaviour with both an Apple USB-C Digital AV Multiport Adapter - and a Kingston Nucleum USB-C hub - both connected via HDMI to a compatible external monitor.

Repeating this test with an identical model iPad Pro, instead running iPadOS 17.3.1, the external HDMI display operates is full screen with Stage Manager as expected. Mirroring can be enabled/disabled with anticipated behaviour.

If you have not already done so, you would be best advised to submit a Bug Report via Apple's Product Feedback portal.

Feedback - iPad - Apple

When submitting a Bug Report, ensure that you include details of your iPad model and installed version of iPadOS within the body-text of your report. Don't rely upon the pick-list - as this rarely includes the current versions. Having verified the bug, I too have submitted a supporting Bug Report to Apple.

Every report counts - as until sufficient reports are submitted, Apple may not assign resources to investigate and resolve the issue.

What do you mean by an input device? Can you tell me what kind and how it’s hooked up? Much appreciated.

how did you get a fix for this

I had a fit when i discovered that the external display support seemed borked once again. I ve since found out that You must have a keyboard and an input device connected in order to have the switch work as before.

After upgrading iPad 12.9" to iOS 17.4, the iPad was not found by my M2 MacBook Air running OS 14.3.1.

Solution: on the M2 MacBook Air, went to Displays in Settings, Advanced, and toggled all three options Off and then On. The iPad was immediately recognized by the MacBook Air, and push through immediately worked.