A problem when you remote control another user and try to elevate to Administrator, using for instance Quick Assist which is built into Windows 10 and 11, or using TeamViewer, the screen on the admin side will freeze. This is due to UAC Secure Desktop feature kicking in.
The solution is to turn this secure desktop feature off, lowering security a little but at hardly no risk.
Configuration via Intune (MDM)
Create a Settings catalog profile and select the Local Policies Security Options setting User Account Control Switch to the Secure Desktop When Prompting For Elevation and set it to Disabled.
Configuration via Group Policy (GPO)
In the GPO editor, go to Security Settings > Local Policies > Security Options > User Account Control: Switch to the secure desktop when prompting for elevation to Disabled