Ad Manager not working after the first 11 Places – is there a cap/max?

I have the first 11 Ad Places working perfectly on my website:

https://experiencedestinations.com

…but when I add in any additional Ad Places I can not get them to appear on the website!?!??! I am using the exact same process/settings for these additional Ad Places, but nothing appears when I place the following code into the pages: [sam_block id=11] (and so on when I try 12, 13, 14, etc)

Is there a max/cap that I am allowed to use? Is there an overall settings or something I need to adjust to use more than 11 Ad Places?

Any help would be greatly appreciated!

Thanks,

https://www.ads-software.com/extend/plugins/simple-ads-manager/