Miller endured another difficult round last week in Barcelona after qualifying down in 11th and could only manage 14th in the race, 34.6 seconds from race winner Fabio Quartararo.
The Australian complained of a lack of consistency throughout the Catalan GP weekend with the tyres and struggled from the off on the harder option rear.
Having finished on the podium at Barcelona a year ago, Miller was at a complete loss to explain the situation.
"Yeah, was a shithouse day to follow up what was this weekend," Miller said after the race.
"[I had] Two decent tyres throughout the whole weekend, I tried my maximum from the beginning but to be honest I had nothing on the right-hand side of the tyre from the beginning to the end, and especially in the end I was spinning in a straight line.
"I don't know what happened with this hard tyre, but it didn't function at the end, doing lap times that I know I can do with the Panigale with tyres from the shelf.
"So, this is not normal, I don't understand what happened this weekend with the tyres but we have a big problem, clearly, because one tyre to the other feels completely foreign on the bike, and then it can come back again.
"I don't forget how to ride, I don't lose my way, the bike we know. Last year I was on the podium here and this year I'm f***ing 30s away without a 1m40s – not one single 1m40s in the whole race.
"So, I don't understand really. We need to analyse, take the data that we get and get an answer.
"We took a gamble in the race hoping it was going to work with the hard tyre, because it was really hot. But it didn't."
Miller said on the Monday test following the race that he his advice heading into the grand prix was to run the hard tyre, but this proved to be the worst option.
"Definitely talked to them [Michelin], but there wasn't much to report," he said. "The circuit increases the problems between the tyres.
"They are working very hard to eliminate this. The choice of hard compound was not good. On paper it all looked good, the advice was also leaning towards the hardest compound. It was not the right decision."
