Comment 17 for bug 1565236

Confirmed for my BT keyboard with German layout (manufacturer: CSL).

In *some* applications, the AltGr-Symbols can be accessed via the "leftAlt-AltGr-key"-combination Timo describes in comment #12 (must be pressed in that order). But this varies from app to app.
In most situations, there is no way of typing the "@" character, which is particularly annoying.

None of the AltGr-characters work in the terminal app (though it sometimes shows undefined characters in response). I confirm the behaviour user 3524 describes in #11 ("(arg: [0-9])" prompt.)

This is on a MEIZU MX4 with OTA 10.1.