After update from 5.6 to 5.715 no sync

I am on a new installed galaxy s5 with lineage.
With an actuell k9 5.6 every think worked fine.
So I updated to version 5.715.
But now there is no longer an automatic sync.
But it is sunday and the weather is rainy so I started from begin and removed the k9 app.
Long story short, the difference between both versions is I dont find in version 5.715 the settings for the push connections.
In 5.6 they are after mail server settings.
In 5.715 the mail server settings are at the end o the list.
Is this a bug or what I am missing?

Ok, now I found this:

I will wait patiently. Thanks for your great work.