Exeter boss Paul Tisdale admitted something needs to change after his side fell to a fourth defeat in five winless games.
The Grecians enjoyed a strong start the season but have now tasted victory just once in their last eight games, with their latest defeat coming courtesy of high-flying Cheltenham's biggest win of the season.
"It's happened once too many times, so it can't be a coincidence," Tisdale said. "At the end of the day we played enough football to have scored a goal, but if we can't defend at crucial moments it's very disappointing.
"I can see the level of play we have, but we've not performed at crucial moments in games. There is a lot of thinking to do after that because it's happening too many times and it's becoming a trend.
"It's very frustrating because we played and passed it so well but we didn't score despite creating so many chances. I want to win games and I am practically minded so something has to change.
"The first goal was the turning point and we needed to score first or it becomes increasingly hard for us. We were loose to the point of the first goal and that's what I must set about correcting."