Apple did not include any TeX distribution with the operating system or within Pages to accommodate associated packages. They incorporated the syntax limited blahtex translator instead. It will convert the (supported) LaTeX into embedded MathML, or the equation editor can accept direct MathML input. I have the full MacTeX 2025 distribution installed in Tahoe 26.3 and Pages could care less…
See About LaTeX and MathML support in Pages, Numbers, and Keynote - Apple Support
I have groujped three objects and with that grouped item selected, here is what I see with your other settings:

Pages is not designed to be more advanced as a dedicated third-party tool like Affinity, Pixelmator Pro, Illustrator, Inkscape, or GIMP. For complex object design, use your pick of those and import the resulting image into Pages.
I have created shapes in Inkscape, imported them into Pages as SVG, and then added them to the shapes library.
Tested: Pages v15.1.1, Tahoe 26.3