Got my 2023 RX 350 a year ago. I have been observing a behavior that the transmission seems to like to select a higher gear than what's appropriate, and this leads to the car sometimes "lugs" the engine.
For example when driving around 20MPH on a slight incline, the car shakes and lugs the engine. I downshifted once and it's showing 3rd gear, which means the car was on the 4th gear before, which I believe is probably too high for that particular situation. I also noticed this when turning at low speed.

I've talked to the dealership and of course they said everything is fine and can't reproduce it Now I resort to two solutions: either manually downshift when this happens or switch to sports mode when I get started, but of course it'll be nice if we don't have this issue at all ...

I'm curious if it's just me or if other people have noticed this, too?

 

Nope, never have felt it was lugging. Sure it’s quick to upshift but every automatic is.

 

I too have not had this problem. Please keep us posted if/when you find a solution. Seems to me that something is not quite quite right.

 

Disconnect the battery for 5-10 minutes. Then reconnect. This will allow the transmission ecu to reset and relearn. Worth a shot

 

no it doesn’t. And it hasn’t for the last 12+ years on Toyota/Lexus vehicles. ECU has persistence storage.

 

no lugging on mine - it's in the gear it needs to be always and shifts awesome

 

OP here, visited the dealership today and told them about the issue again. They did some more diagnostics and applied an ECM update:
I haven't driven it too much but it seems better for now. Will circle back and update the thread once I drive it a bit more.