On Settings all CMS block disappeared

On my OctoberCMS backend, under Settings, the entire CMS section has disappeared.

I can no longer see CMS → Theme or any related CMS settings.

I already checked config/cms.php and loadModules includes Cms, but the CMS block is still missing in the Settings menu.
I also disabled the SEO Storm plugin to rule out conflicts, but the CMS block does not reappear.
Could this be related to a plugin conflict, cache issue, or is something broken in the CMS module?
I attached two screenshots showing:

The Settings page with the missing CMS block.

The menu structure (left sidebar / Settings) for context.