Transmission Flare on De-acc

Hi Guys. Have a 2013m Prius C i-Tech, with just under 70,000 kms (43,000 miles). It's been very good, but recently have noticed the engine revs higher when de-accelerating. It's as if there is a disengagement of the transmission for a few seconds. This is a new phenomenon starting around 2 weeks ago. No fault lights and all other aspects OK. I do my own servicing as have a small workshop, but have only done oil & filter stuff. So then, has the transmission got a fault, or a software problem, or some other strange thing. I have been scouring the forums and the issue seems to be a loner. The only change in driving situations is that 3 months ago we moved to a new home in an estate, and it has a km or so of downhill driving at 15 kph (reality is usually 25kph) and there may be a problem with the adaptive learning of the transmission. However we have lived here for 3 months now, yet the problem has been only for 2 weeks. Great forum BTW

 

Hi Bisco... Seems to be only when coming off an acceleration phase, and not really related to braking, can be going over a hill, then lifting foot off accelerator, or after a quick goosing of the accelerator. Next I will scan with the GScan unit. And don't feel obliged to diagnose, as these things can be near impossible, but so much appreciate your input