Tracking from one website doesn't work

Hello,
a lot of visitors come across a forum on my website. there I have in my signature a link to my page. “www.tecsupport.de”
but for a few weeks I get no longer displayed in slimstat. all other sites function properly.
only this one forum page is not shown as a start point.

what can I do ?

excuse my English. I am German and use google translate)

https://ww.wp.xz.cn/plugins/wp-slimstat/