I em having problem with writing diacritics using compose key (https://en.wikipedia.org/wiki/Compose_key) in Czech keyboard layout. This key should be right before backspace (in standard keyboard it is key for + and =). And it is there because acute (https://en.wikipedia.org/wiki/Acute_accent) diacritics is fine (using this key without shift), but caron (https://en.wikipedia.org/wiki/Caron) is not working (should be this key with shift).
For example á,é,í,ó,ú is ok. But d,t,n should be ď, ť, ň.
I em not sure for how log this is happening, but maybe one or two month (I did not use this letters very often).