Can't change font size in Elementor Text Editor Typography - when using Shapely theme

To produce the issue:

Create new or edit existing page and edit with Elementor.
Place a Text Editor object and add some text.
Change it to Mobile Mode
Go to Style tab of the object > Typography > Select PX, EM … attempt to change the font size… No reaction, doesn’t work.

Changing paragraph to bullet point list it works.
Changing it to any Heading type or Paragraph, doesn’t work.

We turned off ALL plugins, all editors.php and CSS are default.
Wordpress (V6.1.1), Shapely theme (V1.2.15) and all plugins are up to date.

After troubleshooting, the only way we could overcome this issue is by deactivating Shapely and using a different theme.

We dont mind changing theme however, the entire site stuffs up and will need rework which is extremely time consuming.

Elementor said this is not their issue and have to contact the theme developer.

The paragraphs are appearing really small on mobile devices which is why we need to increase the font size only on Mobile.
Sample site here:

Please advise? Thank you.