How to open new tab in the current gnome-terminal window

I don't know if you're still running into this issue, but I found my problem was I was running /bin/zsh as a custom command in my terminal profile. Disabling that fixed the issue for me - and still kept zsh as my primary shell.

A very simple workaround for you would be including a function in your ~/.zshrc that remembers the working directory and changes into it when opening zsh:

cd $(<>/dev/shm/$USER-pwd)

__cd(){
    \cd "$@"
    pwd >/dev/shm/$USER-pwd
}
alias cd=__cd

We use /dev/shm instead of /tmp to avoid disk writes, although /tmp could already be a tmpfs on your system. \cd is used to avoid a fork bomb.

If you would like this feature for gnome-terminal only, you could include an if statement to check your current terminal or active window. Also, if you are concerned that other users might find out what was your last directory, you could modify the permissions for $USER-pwd with chmod:

if xprop -id $(xprop -root 32x ' $0' _NET_ACTIVE_WINDOW | awk '{print $NF}') WM_CLASS | grep -q gnome-terminal; then
    cd    $(<>/dev/shm/$USER-pwd)
    chmod 600 /dev/shm/$USER-pwd

    __cd(){
        \cd "$@"
        pwd >/dev/shm/$USER-pwd
    }
    alias cd=__cd
fi