@GSC1 and @mnr have raised this last June and November, but there were no replies.

mnr posted this (rpresentation vs mathjax & preview pane ) in early June with no replies. I never had any issues until I upgraded both R (from v3 to v4) and R Studio, and now I have the exact same problem as mnr.
I feel the live MathJax engine isn't properly linked to the Presentation pane, because if I use a browser to open the HTML version of the presentation, the math looks perfect.
I'm trying to embed math in an Rpresentation, then show it in the Rstudio PRESENTATION pane.
Code sample...
solve() for systems of equations
========================================================
author: Mark Niemann-Ross
date:
autosize: true
Solve a system of equations
===
As an example, start with this system of equations:
$$
2x_1 - 3x_2 - 1x_3 = 2\\
1x_1 + 2x_2 + 3x_3 = 15\\
5x_1 + 1x_2 - 1x_3 = 4\\
$$
Then I click on the Preview tab. The presentation (not the viewer) pane correctly shows the title slide. Then the second slide shows the latex instead of the rendered formula. i.e.
As an example, start with this system of equations:
[ 2x_1 - 3x_2 - 1x_3 = 2\ 1x_1 + 2x_2 + 3x_3 …

Basically, math equations are not render in the Presentation pane.
They're rendered OK in the Viewer pane, but a bit cumbersome to do.
Any fixes or advice would be very welcome!

Cheers,
X.