Exeter boss Rob Baxter has questioned the "collective drive" of his team after the double winners suffered a second successive defeat.
The Chiefs were outplayed in their top-of-the-table, 20-7 defeat by Bristol, a biggest home defeat in four years following last week's loss at Wasps.
"We probably are in a little bit of an emotional wobble," Baxter said.
"I'm not quite sure that every game is meaning quite as much as it needs to at the moment for the lads."
Exeter last lost back-to-back games when they played weakened sides at the end of last season, once they had already secured top place in the Premiership.
Prior to that, they had not lost successive league games since a three-match losing run in January and February 2018.
The losses mean last season's double winners have dropped to third in the Premiership behind leaders Bristol and second-placed Newcastle, who beat Gloucester in Saturday's other match for their fifth win from six games.
"We had a big end of the (last) season and you think there might be a flat spot coming at some stage. It feels like we've hit one now," Baxter told BBC Radio Devon.
"But there's only one way to get through it - you get honest about it and you get some hard work done.
"If I'm going to question the lads, and I don't often do it, I'm not quite sure at the moment that they're prepared to throw absolutely everything into a game," he added.
"I'm not saying that completely across the board, because there's always players who are going flat out, but I think that collective, absolute flat-out drive and will is just a little bit off at the moment.
"The good thing is that can come back very quickly if you deal with it and you're honest and open about it."