This is a Windows issue, and there is an easy two-part fix. 

You will need to open the Settings panel.

[1] Then, Click on the Painter icon in the Application row. The instructions are listed below if you have not added Corel Painter 2023 to the Application row.

[2] If Windows Ink is not checked, you will need to check it. 

Open Corel Painter 2023.

[3,4] You will need to select Edit > Preferences > Tablet.

[5] Make sure the radio button for the RTS-compatible device (Real-Time Stylus) is selected.

The eraser should now be working as an eraser. 


Adding an application to the Application row: