Ben Whiteman had hauled Frankie McEvoy's side into a first-half lead before Scotland star Matty Phillips' strike earned a point for the visitors just before the break.
West Brom have now drawn to Millwall, Derby and Preston in the space of a week and Ismael insists it is about time they discovered their edge in front of goal.
The former Barnsley boss, whose team lie third and two points adrift of table-topping Bournemouth, said: "The problem today was the quality of the final pass and the quality of crosses - they were not good enough.
"When you get a chance to score you have to take it - and we have to develop that killer instinct in front of goal.
"We tried everything in the second half - we showed the right mentality and that is a good thing. But we have seen that we need to work more on what we do in the final third.
"I do not think it was the same picture from the team today as it was against Derby, it is as simple as that for me.
"Our opponents today had two shots on target in the whole game and scored a deflected goal against us.
"They took the lead, and we came back into the game before half-time which was important as it gave us some key momentum.
"But in the second half it was exactly like Derby in terms of performance."
Neither team created much in a timid opening as Adam Reach, Patrick Bauer and the busy Grady Diangana all had half-chances.
And it was the hosts who hauled themselves in front just before the half-hour mark when Whiteman's deflected strike flew past England international Sam Johnstone in the West Brom goal.
The Baggies responded to show their promotion-chasing class just before the break, however, as Phillips produced a deserved equaliser after Darnell Furlong's long throw-in caused havoc in the box.
Both sides sought to grab a winner throughout the second period and while Diangana, Ryan Ledson and Norwich loanee Jordan Hugill all went close, the two teams held each other to another Championship draw.
McAvoy, whose team have also drawn three on the spin and lie 17th in the table, said: "The players have done what I asked them to do today and I am pleased with that. The guys have absolutely worked their socks off right from the start.
"They gave everything out there today and because of that, thankfully we have kept our unbeaten run going,
"We knew what was coming from West Brom after the break and the team reacted brilliantly to it.
"I'm delighted by the way we stood up to the challenge in front of us - we knew the second half would be a tough battle against a good side, and thankfully we have managed to keep our unbeaten run going.
"If you lose two and win one you still have three points. The most important thing is psychologically, we have come back from losing those first three games.
"We now have nine points on the board from a possible 15 and we're looking okay so far this season."