Website only shows 1st category page (10 posts) – page 2,3,4,5…NOT FOUND

All of a sudden the website only shows the first 10 posts of each category page, if u want to go to page 2 the website says:

PAGE NOT FOUND OOPS! THE PAGE YOU WERE LOOKING FOR WAS NOT FOUND. 404

Already tried to disable all plugins without any success.

Example: https://www.kickboxingplanet.com/news/

I want people to show my full database of posts off course. Anybody an idea what the problem could be?

Don’t know for how long this has been the case. It’s not really something u check regularly…

Thanks in advance,

Roy