The brushes are easy and cheap enough to replace that it's worth a try, take the holder to an auto electrician and see if they can help you.
It helped briefly on one I was trying to fix but the problem came back...
We suspected the electromagnetic powder clutch, it's not a torque converter, there is a kit to replace the powder in the powder clutch but it's a gearbox off job. I wouldn't be sure that's what's happening here though, on the car i had it would try to stall once coming to a stop and would also be difficult to get into drive.
There's an adjustment on the gear selector that you could also check is within spec.
Powder clutch kit:
Magnetic Clutch Repair kit
cvt-parts.co.nz
I gave these guys a call and they were very helpful, I also retired replacing the cvt fluid but no joy there either...