The system restart (the button sequence described above) has fixed it for me every time, which has been 4 or 5 times so far over the last six months. Does not change any settings or preferences, just takes a couple minutes for the TV to restart.
and for the record system restart, pulling the power cable and hold power button dont fix it, my tv has has action smoothing / motion smoothing bugg for while. And i am not gona keep factory resetting my tv to fix temporally just for to happen again. and have to "change" any picture setting back to what I want them on
there is no difference from OFF and LOW as now, OFF and LOW does same thing to tv image, switching from LOW to MEDIUM there difference and from MEDIUM to HIGH there is difference in that the effect of action/motion smoothing is more apparent.
Every Input and every picture setting including SDR/HDR setting have it set OFF. but look exactly like LOW
I am disgusted by this the 2 S515 I have have this issue I have another TCL 32" that dont have the ability to do action/motion smoothing and video look like it should.
But hey the HDMI handshake issue in the intial 9.4.0 build is fixed and Gamemode works to about as well as it did in 9.3.0 where it random stop engaging and needed the TV to be restarted that has happen at lest twice so far. But i dont have to worry about Action/Motion Smoothing issue so long as gamemode works cause it DISABLE action/motion smoothing at same time it reduce input lag.
I am seriously amazed that there mutiple tv brand that let "roku" push this update to there tv that break mutiple brands and models to have the same issue
I was the one who originally started this thread back in April of 2020. All this time later, I’m still having the exact same issue on my TCL-75617.
Even with all the motion interpolation settings off, I still get motion smoothing, especially on HDR settings. This is really disappointing that both ROKU and TCL refuse to fix the issue and keep passing the buck onto the other.
if this doesn’t get resolved soon I’m going to have to cut my loses. I’ll sell the TV and find something else. More importantly I’ll never recommend another ROKU or TCL product to anyone I know.
I haven't read through this entire thread, so I don't know if this has been mentioned... we also had this issue with our 75R615. I always made sure the settings were set correctly, but smoothing would return after what seemed like a random amount of time and the workaround was to reboot the TV. But I found the culprit on our TV -- on our last TV we had a Roku Ultra and the "Aquatic Life" screensaver was set as the default. We really liked that screensaver, so I downloaded it on our new TV. It ran fine (although not quite as smoothly as it did on the Ultra), but we figured out that when that screensaver ran, it was causing smoothing to return, even though the settings still showed it was disabled. I uninstalled the Aquatic Life screensaver and our smoothing hasn't returned in the past several weeks.
So Aquatic Life was the problem on ours, but I imagine it could be caused by any screensaver or app that switches the display mode and somehow flips on the smoothing.
I didn't have anything else installed that I'd consider non-standard -- just the Aquatic Life screensaver, and it was the only thing I uninstalled to fix the problem. Every time it would come on, the screen would go blank for a second or two, then the screensaver would pop up and you could tell it was switching to some sort of special display mode, like when you start a video game on a PC and it starts up a different graphics mode. So I think that screensaver had the ability to enable smoothing for itself in the background but didn't turn it back off when the screensaver ended. That's just an IT guy's guess. :-)
That's very interesting, I had the issue on my TCL and have approached the problem by doing a system reset and disconnecting the TV from the internet for the last 4+ months, and have had no problems. Now, I do know for sure that when I was experiencing the problem, we had the aquatic screensaver installed and enabled. I can't confirm that it was the cause, but it does match up with your experience.