This could prove useful. It mentioned you need to press the tilde
key twice!
I am happy that this solved your problem.
.... Take me: I have realized the difference by
serendipity by looking into the layout file and instantly switched to
the traditional behaviour. Really, I have just jumped into the Linux
world in March 2015, I am not just obdurate in this matter. I use the
traditional layout because dead_tilde and dead_macron in the layout
are simply more useful than asciitilde and macron in general.
Programmers have their accentless layout or use a non-German layout
completely, if they need keys commonly implemented as dead keys too
frequently and on the other hand do not need accents, but for most
computer appliances it is smooth to press the dead key twice. Whereas
nothing speaks for keeping the mixed keyboard layout resulting from
the often-cited standard. Again, who knows what is set elsewhere?
People come to use free desktops because they want to learn, and in
the unlikely case that the dead tilde surprises anyone, he does
appreciate it if he owns himself to conceive its use.