Haas suspects the thinner tread of Pirelli's 2019 Formula 1 tyres may be a key factor in causing its race day struggles this year.
The team is still chasing answers over why its strong single lap pace in qualifying falls away in the races, when it has difficulties keeping its tyres in the right operating window.
Romain Grosjean thinks that the thinner tread that Pirelli is using throughout this season - which it ran at three events last year - may be the answer.
"We think that's what's hurting us," he explained.
"That's the only explanation we have, but some other teams have done a much better job in getting them to work.
"Sometimes they work and you don't know why and you don't ask yourself why.
"It happened to us in 2017 in Austria (pictured). We were flying, don't ask us, it just worked. We tried to repeat that, same number, same temperature - but never got the same.
"I wish Formula 1 was easy in that aspect and we could have a bit more fun playing around with other settings."
World championship leader Lewis Hamilton said that even for him the new Pirelli tyres were proving tricky to master.
"The tyre this year seems to be a little bit more complex this year than last year, [in terms of] understanding it," said the Mercedes driver.
"But at the beginning of every season we always struggle, and everyone is trying to understand the different tyre windows you are in.
"The window of these tyres is even narrower than it has been in the past, which was pretty small before and is even smaller now."
Red Bull's Pierre Gasly agreed that the change of tyre specification for this year was having a significant effect.
"It seems to be quite difficult on traction, but it's difficult to know whether it comes from the structure of the tyre or just the fact that the tread is shorter," he said.
"It just seems they are quite tricky, not so much in terms of degradation, but in terms of traction on the exit.
"There is no issue, but it's like everything, if you really want to maximise and make the best out of everything it's difficult to get the last percent."
Grosjean said Haas has brought some new upgrades to Baku to try to improve its situation.
"We've brought some new parts and we're hoping that's going to help us," he said.
"Obviously it's about getting the tyres to work. If that's not enough yet, we need to look at more, but it's definitely there."