Sometimes return key and tab key doesn't work as it should be

Thanks for making an awesome terminal for the windows. This is way better than the other terminal emulators in windows I've ever used.
However, I have to hit the return key twice sometimes. It seems that it puts return keys directly for the terminal buffer itself rather than sending key directly to the underlying app (e,g. zsh) This also seems to explain the similar bug: tab insertion. I regularly use TAB to autocomplete in my shell, however, sometimes it puts tab character rather than invoking the autocompletion.
It doesn't seem to happen on the Powershell core. Always happens on the WSL. Turning ConPTY off seems to help.
I'm using zsh, and oh-my-zsh on FT 0.6.1.0. Line ending translation doesn't seem to affect it.