Nissan Micra K11 NCVT gearbox defective

Hello, I hope I find here useful help. The following problem: I drive a great Nissan Micra K11 with all the drum and drum. Also with the NCVT automatic transmission. This transmission worries me now. Error description: If the engine is off, the transmission can be switched off quite normally. From P to R to N to D and back. As soon as the engine runs no more gear can be put in. When trying to set a gear, whether R or D, it only makes terrible noises. Well, I was On the road and still had to go home, so I choked D in and my car rolled immediately without giving any gas. Otherwise, my car ran quite normally and quietly as always. The gearbox switched all the gears straight through and worked inconspicuously. At least until the next traffic light. There the engine was “stirred” by the gearbox as if I would not kick the clutch in a manual transmission. Well, I then made it home with much trouble and luck. There is my best piece of work. I don’t dare to drive a meter anymore. I don’t want to break it anymore. I’ve received the following advice from experts so far. 1. Nissan contract workshop: “Shifter belt (what is it?) is defective – replacement gearbox – 2600 Euro material costs.” 2. Gear specialist: “Magnetic powder coupling (what is it?) is defective – new part 1100 Euro material costs.” 3. A friendly mechanic: “If the gearbox has a magnetic clutch your error could also ele “Hail! Please give me some valuable and cheap tips. I am very grateful to all of you in advance. Greetings Monika