All combined letters are not working for me on beta 4.
e.g., I can not type the caret or all characters with a caret, like âĉê.
Same for the grave accent (e.g. `à èì)
My system:
OS Version: Ubuntu 16.04.5 LTS
Kernel Level: 4.4.0-134-generic
Processor Architecture: x86_64
Language: German