Buy Button Disappeard

Hello you all,
I have an Eduma theme and had my course up and running regularly.
Now I noticed that the Buy Button has disappeared and people cannot buy any course.

I haven’t changed anything, the website is finished so it must have been an automatic update of something?
I find it not nice that when there are updates often the website start showing problems.
Last time I had a different problem as well but this is really important. I have people willing to buy.
Can you help me?