Insert multiple excerpts from the same page

[Nic Brough -Adaptavist-]

It is for Cloud, so the version is "latest"

[Guus Biemans]

Is there a maximum on exerpts to create on the same page?

After creating 13 excerpts on the same page I get this message when including one of them on a new page:

You have duplicate excerpt names. 
To select the excerpt you want, give it a unique name on the source page.
Go to source page  

 This is clearly not the case.