Black Dot Pattern on Video of Participant during 1-on-1 Zoom Meetings

When conducting 1-on-1, standard Zoom meetings, the participant I have invited, or who invited me, has a black dot matrix pattern superimposed on their screen window when I view them.  They do NOT see the pattern on my face from their end, and I only see the pattern lightly over their face when their video is on (Note: there is no pattern if their video is off or when they share their screen).  When I'm in a meeting with more than one participant, I do not see the dot pattern if there are more than one participant, beyond myself, in the meeting (that I can recall).   I am not aware that I ever adjusted any settings in my account, and I do not see any settings which seem to address this issue.  Thanks! 🙂