By model number you appear to have an iPad Pro 11" - of which all models should support Stage Manager.
Your initial comment as to connecting your iPad to the monitor "by HDMI via a cheap USB-C hub" is perhaps a concern - as its functionality and capability are an unknown. The hub and/or cables making the connection may themselves be the source of your difficulties.
As a diagnostic exercise, substitution of both your hub with a known good HDMI Adapter or USB-C hub and good quality HDMI 2.1 cable would be advisable. By example, if connecting via HDMI:
- Apple USB-C Digital AV Multiport Adapter
https://store.apple.com/xc/product/MUF82ZM/A
![](https://discussions.apple.com/content/attachment/a141b319-03c2-4140-b7a1-0b44af075251)
Otherwise, with your existing arrangement, try a forced-restart of your iPad - as this will often clear an isolated iPadOS software issue:
Force restart iPad (models with Face ID or with Touch ID in the top button)
If your iPad doesn’t have the Home button, do the following:
- Press and quickly release the volume button nearest to the top button.
- Press and quickly release the volume button farthest from the top button.
- Press and hold the top button.
- When the Apple logo appears, release the top button.
![](https://discussions.apple.com/content/attachment/731c5ed0-803c-43ad-94d2-bb144d52ba3a)
If the problem persists after performing the restart, it may be necessary to reset your iPad settings. While this reset will not cause any loss of data, as a precaution, it is always wise to ensure that you have a current iCloud or iTunes backup before performing the reset:
How to back up your iPhone, iPad, and iPod touch - Apple Support
When you are happy to proceed, you can perform the reset from iPad settings:
Settings > General > Transfer or Reset iPad > Reset > Reset All Settings
If the problem still doesn’t clear, the next step is to reset the iPad to factory settings:
Restore your iPhone, iPad, or iPod to factory settings - Apple Support
Should the issue remain unresolved, you might be well advised to seek assistance directly from Apple Support - but be aware that you will likely be advised to substitute the USB-C hub and cables as previously suggested.
You can contact the Support Team using the Support link at top-right or bottom-left of this page. Alternatively and perhaps easier, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians may be able to assist:
Genius Bar Reservation and Apple Support Options - Apple