20 collection limit on CMS Plan?

We are trying to add a collection on our site and it shows a message:

You’ve created all the collections allowed by your CMS Hosting Plan. To add more, upgrade to Business Hosting.

I have read through the pricing plans and the only limitation regarding CMS is the Collection items (Max 2000 in CMS Plan).

Anyone has an idea why this happens?

Thanks in advance for the feedback.

Best regards,

Here is my site Read-Only: LINK
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