Pen cursor is invisible over white areas in PowerPoint (presentation mode) while screen sharing

Running most recent versions of Windows/Office/Zoom.

I have a pen tablet that works well with PowerPoint, but as soon as I turn on screensharing in Zoom the cursor becomes invisible while over a white background in the slide while in presentation mode.  If I use the pen to annotate (ppt annotation, not Zoom annotation) it becomes really difficult to work with it.  I have been using it without this issue for about a year, so this behaviour is new but I'm not sure if it is a result of updates to the Zoom client, Windows, or PowerPoint.

According to meeting attendees, they can see the pen cursor, so this seems like it is probably a Zoom issue, but I can't be sure.

Edit:  Just tried this in MS Teams and the result was exactly the same (missing cursor over white areas), so I guess this is not a Zoom issue after all.

I can use the Zoom annotate as a workaround, but I prefer to use the native function in PowerPoint for a number of reasons.