Mercedes won three of the four races that came before the summer break, but they were not competitive at Zandvoort, where McLaren’s Lando Norris won handily and George Russell finished seventh, one spot ahead of teammate Lewis Hamilton.
The Silver Arrows were this weekend using the new floor for the second time, having abandoned it after Friday practice at the previous round in Spa.
Without the part, Mercedes took the chequered flag in a one-two, before Russell had his victory taken away due to his car being under legal weight.
With Mercedes having just a few days to prepare for next weekend’s Italian Grand Prix, team principal Wolff said:
“I think these cars are sometimes a surprise-box. We’ve had six [races with] podiums in a row and that doesn’t look like the car three weeks ago that was first and second, at least first on merit.
“You can’t really end up with a result like this without any major factor playing, and that’s something we need to analyse in the next few days until Monza.
“Was it because we put something on the car that didn’t help? Did we engineer something into the car that wasn’t good?
“Then how do you justify these swings of performance? Sometimes we looked really good this weekend and then obviously today, in terms of degradation, that was not very impressive.”
Mercedes’ task – along with the rest of the field – was made more challenging by much of the weekend’s three practice sessions being lost to bad weather.
Wolff explained that the limited running had made it hard for Mercedes to assess the data from Friday when they ran their two cars with different floors.
He said: “We back-to-backed the update kit on Friday, which was at the end left us with not a lot of data – the update kit that we put onto the car in Spa on Friday and then took off again.
“And then obviously with the lack of running, like everybody else, maybe it didn’t decide the right things for the car. So, there could be a few factors in play that contributed to this non-performance.”
Asked if he thought the issue was specifically the floor, Wolff added: “I don’t want to jump to conclusions too quickly because we’re going to look at it the coming days and hopefully trying to find clues in the data.
“Was it a setup? Was it the track? What is it that we got wrong? Was it the floor that we put on the car? Was it all of this together?
“So, hopefully we can sort it out until Monza and become competitive again. But the swing in performance from P1-P2 and P7-P8, there’s a biggie in there. It’s not something that was simply a setup decision in my opinion.”
Russell started from fourth after a decent qualifying effort but lacked pace in the race, dropping backwards having run third for most of the opening stint after passing Oscar Piastri at the start.
A slow pit stop saw Russell lose a place to Charles Leclerc, but his pace afterwards was poor and he was passed by Piastri, before a further stop due to high tyre degradation saw him lose further places to Carlos Sainz and Sergio Perez.
“I don’t really understand what has happened, in all honesty,” Russell told Sky Sports F1.
“We were slow on all three tyres and went backwards.
“It was weird how we qualified fourth and were consistently just behind the three cars in front and in front of the Ferrari and it all disappeared.
“It just felt like it had no grip, sliding around like I was on ice. Something to do with the tyres. We definitely got something wrong somewhere, but I am scratching my head.
“This is definitely an outlier. We have been there the last six races. Performance does swing circuit to circuit, but this does seem odd. It’s strange we have won three of the last four then finish 50 seconds behind the win today.”
Lewis Hamilton and Carlos Sainz failed to make it through to Q3 after a surprise Q2 in Zandvoort.
It was always likely to be a long afternoon for Hamilton, who started from 14th on the grid after a shock Q2 exit was compounded by a three-place grid penalty for impeding.
The seven-time world champion was actually pleased with race pace as he battled forwards, and suggested he could have competed for a podium had he started in his team-mate’s grid slot of fourth.
“I was much happier today,” Hamilton told Sky Sports F1.
“I was moving forwards, progressing, moving in the right direction, just too far back unfortunately.
“Even though I had a lot of understeer in P1, the car felt great and even for P2. Then we made this change overnight because we had so much understeer and it flipped it. We backed out a bunch of wing for the race and I was progressing.
“If I qualified where George was, then I think I would have finished at least there, if not further ahead.
“I think we could have been close to a podium. I don’t know if we were faster than Ferrari but there were elements of our pace that was strong.
“The car was not great compared to the last race, when we had a lot more pace. We were closer to others today.”
