I wouldn’t sit on the terrace in that location for the reason of the OP: getting ignored.

Whenever I sit on the couches near the bar, the service has been good because staff to and from the bar either see you, or you can flag them down.

In the dining room has been very good for me too.

But: I feel for the OP - many people don’t like to speak up. My Aussie mother never would and yet the New Yorker in me would get up and just walk to the bar or a staff member (if it had been 10 mins and now one had come by).