Thanks for filling this.
However none of the other users have complained. I somewhat believe that is due to your Windows_NT x64 OS. On Windows 10 I can not reproduce this issue - I just tried with latest vscode insiders.

@alexandrudima I guess the font size is required to be set here otherwsie other things would break.

The magnifier also works fine for me on Windows 10 . It follows the cursor fine.

I would like to be able to reproduce before doing a code change, I don't understand why the fontSize would be relevant for the magnifier without at least reproducing.

@JiayangShen are you on Windows 10?

The magnifier also works fine for me on Windows 10 . It follows the cursor fine.

I would like to be able to reproduce before doing a code change, I don't understand why the fontSize would be relevant for the magnifier without at least reproducing.

@JiayangShen are you on Windows 10?

Yes, it is on windows 10 (Windows_NT x64 10.0.17763). And I find that except remove the font-size, if set font-size bigger then 1.67px, the magnifier also works. emmm...it is really too strange! if can't remove font-size, can set it to another value? for example, 2px? I have tried, set font-size equal to line-height size is the best value for magnifier.

I also tried the insiders version, it has the same issue.

@JiayangShen I would still like to reproduce, so I can check that the code change makes a difference... Are you perhaps on a high DPI screen or otherwise using this zoom option in Windows or the window.zoomLevel setting?

@alexandrudima thanks for your idea! After I set the editor's window.zoomLevel value to 0.1, the magnifier works! the default value 0 does not work. Or, press ctrl and use mouse wheel to zoom in the editor, the magnifiter works too. if zoom out and let the font-size small enough, magnifier will not work.

I verified by comparing behavior of the following steps in stable and insiders:

1. Set zoom level to -8
2. Open an untitled file and type many lines of text
3. Navigate the document up and down using the editor cursor

Stable: magnifier stops tracking cursor
Insiders: magnifier continues to track cursor

I verified by comparing behavior of the following steps in stable and insiders:

1. Set zoom level to -8
2. Open an untitled file and type many lines of text
3. Navigate the document up and down using the editor cursor

Stable: magnifier stops tracking cursor
Insiders: magnifier continues to track cursor

Same here, I will have to use the Insiders version then. Thanks for the tips!
Also the text following feature is not working in the Terminal view, at all with both VS versions on PowerShell and CMD. It's sad cause I'm using the console a lot. Should I open another issue for that ?
Thank you!

After applying my settings to the Insiders version, I noticed the same issues, so I tried to find which particular setting was breaking it.
And finally removing the line "editor.accessibilitySupport": "on",
inside C:\Users<USER>\AppData\Roaming\Code\User\settings.json

made the trick, so I guess this mode should be buggy.

This fix is in the vscode stable also, so you do not have to switch to insiders.
editor.accessibilitySupport: "on" should not have an influence on this feature.
If that is no the case, can you please create a new issue with minimal reproducable steps so we look into it. Thanks