Keynote not showing fullscreen slideshow on Google Meet

Please, help me figure out this mystery:

I am running the same Apple Keynote version "13.2 (7038.0.87)" and the same version of Google Chrome on two different Apple silicon Macbooks (M1 and M3 Pro) both running the same 14.3.1 version of MacOS Sonoma.

When I'm using the M1 Macbook to run a Google Meet through Chrome, then share my general Keynote window, people on the call see only my Keynote window. When I start the slideshow presentation (clicking on "Play" in the Toolbar), Keynote goes fullscreen in my view (as it is the behavior I set it to), and everyone else on the call can only see the slide that is occupying my entire screen, the transitions as I go through the slides, etc.

As a proper presentation should go.

When I press Esc. to leave the slideshow view, people on the call go back to seeing only my Keynote window.

And that's great. I love that workflow and that's what I want and expect out of Keynote and Chrome.

HOWEVER, using the M3 Pro Macbook to perform the exact same task, in the exact same way, with the exact same versions of the same softwares and systems, I get a very different result:

Keynote goes fullscreen in my view (as I set to) BUT everyone else on the call continues seeing only the static Keynote window, no slides going fullscreen, no switching... no presentation.

I've mirrored all the settings for Keynote on both machines as far as I'm aware.

All the security, sharing and recording permissions also seem to be the same between both machines.

BUT WHAT AM I MISSING? How can I get the M3 machine behave like the M1 machine?

What configurations, settings or permissions could be causing this discrepancy?

Please help me out and thank you in advance!

P.S.: I am aware that I could set the slideshow to be played in the "windowed" mode and share that window through Meet, it's just not practical to me. Specially because the other way is clearly possible, so it would be silly to find a workaround to something that already works. =)