This is true.
> Men usually wear a baseball-cap over the Kippah in public
But this is right-wing bullshit.
The rise in anti-Semitic crimes is used by Pegida to stir up fear of refugees, Muslims, and Islam, and it's also used by Netanyahu and the Israeli / Jewish right to encourage immigration to Israel.
The reality is that the rise in anti-Semitism begins in 2014, prior to the refugee crisis. It's tracked the Europe-wide rise of the right, not anything related to "Muslim integration" (which in turn is often a code-word for not letting other people wear other kinds of head coverings). Much of it is even linked to Pegida-adjacent groups or people.