Upgraded test site to J4 (awesome by the way)
(upgraded from 3.1.x via installer)

Module Positions
OK = js_side_frontpage
All other js_xxxx positions missing

When trying to create module position in Extensions/Module Manager, added js_side_frontpage_top and Saved.
Position is listed as "none"

This server info is for out Test site, not the live site.

FYI we did turn off compression in our template

HI.

All built-in module positions are there. Please check our documentation:
documentation.jomsocial.com/wiki/Built-in_Module_Positions

Built-in positions will be not listed in Joomla! module positions list - it's because Joomla! is "aware" only about TEMPLATE positions (as those are "reported" in xml file). So if you want to assign module to built-in position - you'll need to type in module position name manually.

Only if you have at least one module assigned to certain built-in module position - it will be listed (doesn't matter if module is enabled, disabled or trashed).

Got it.
Did that.
Figured they were really there, just trouble assigning and viewing them in module manager.

Created module "grouptest" and assigned it to js_side_frontpage_top and position is not displayed, module is not showing up on site.

Perhaps I've done something incorrectly in assigning the module position.
js_side_frontpage shows up in the list but nothing else does

Everything works !

It was a typo in the setup.

When creating the custom position, clicked on Add Custom Position and it did not create position.
Typed in custom position and just hit Enter and it created position and displays correctly.

Thank you.