I thought some of the bugs and glitches were going to be ironed out with this update but they're still there with new ones popping up left and right now the loco is fusing with the train car.
If you are trying to couple up to the cars, there is something you will need to do first before coupling to them. Stop your loco just before the set of cars, then get out of the loco and walk up to the cars. Then click on the coupler to close it then you should be able to couple up with no issues.