I almost always get filled between the bid/ask on highly liquid ETFs and stocks - and usually very quickly. It can be a little harder if you're trading spreads, but it doesn't sound like you'll be doing that. Also, it may depend on your broker, as someone mentioned.
But when it takes a half hour to get filled, that makes no sense to me.It's not normal for me on TOS, but I don't know about IB. Maybe it's because it's an index. I trade SPY.