Remove ‘read more’ in posts

Hi, I’m building a WP-site for the first time and I manage to use SiteOrigin which works great!
http://silviamuller.nl/2017/acties/

But …. I’ve removed the words ‘read more’ when I enter the read-more-tag. I’ve done that because I think it’s more stylish and besides that there is a button at the bottom of the message.

http://silviamuller.nl/2017/

But now I’ve used SiteOrigin on the message ACTIES (bottom left) the read more tag appears in the message (translated: ‘lees meer’)!!! And ….. it even doesn’t work.

How can I remove that?