We have implemented a workaround for the language issues that occur when these remotes are seen as a keyboard (to enable long-press support) and some keyboard layouts (including de). These fixes are specific to particular dongles and the remotes intended to be used with them. Prior to this thread we have only been made aware of one other system suffering this issue and that was caused by using a dongle that was not correct for the remote it was paired with.
So we can understand if this is also the case with your system or if there is some other issue that needs to be looked into I would request you submit logs as well in the manner I outlined above.