Please find more information here.
PC version Windows 10 TeamViewer ver. 15.4.4
On a phone with android 8.1.0
I have a Host 15.4.3
myPhone_Hammer_Energy_18x9_**Please do not post TeamViewer IDs**79
Connects to the phone but the cursor does not work. You can't click on anything.Why?
Did you see a message to install an add-on to the phone? If yes did you installed it? It could be needed to start the installation procedure from again.
Also, please try to disable the screen autorotate in landscape mode for a moment to see if this changes anything.
I hope this helps you to solve it.