I can not explain this but this seems to be solved.
Using Autoptimize already but now aggregating javascript in stead of minify did the job. I could not do this before because it made Contact Form 7 fail to redirect to a “thank you” page after sending a form. With the help of the author that has been solved so that I can “aggregate” now.
I saw people from all over the world visiting my site. Thank you for your intention to help. Moped, especially to you!
Regards
Rudolph Smits, Netherlands