Refernce list cut off at 50 items

Hi gaian,
after having resolved the incompatibility problem with other plugins today I run into the next one on my site http://www.cienagagrande.co on page: http://www.zonacostera.info/CGSM/biodiversidad/

89 items of my library are tagged with “biodiversity” according to my home computer and online list. Smaller issue:with zotpress brows I get reported 93 items…Why – no idea?

Bigger problem: with [zotpress tag=”biodiversidad” sortby=”creator”] I get a list with exactly 50 items. Any idea why this might happen? By the way this also happens when I put the items in a collection and call it by the collection key.

Similar issues happen on other pages of the same website, e.g. on the very first page, where also more items should appear: http://www.zonacostera.info/CGSM/

Thanks for your help!
BR, Horst