Problem:
Using the call X"A7" function 17 to hide the cursor does not work, a thin line persists on the screen.
Resolution:
The call-by-number call X"A7" function 17 cannot be used to set the cursor to invisible (hidden).
It is possible to hide the cursor in a character-mode linked program (EXE build).
The CBL_SET_CSR_POS can be used instead of call X"A7". See online help.
Or the WinApis CreateFile and SetConsoleCursorInfo.
The attached demo shows, how to do each of them.