Petrol, 1.6 l. 82 kW / 111 hp: vehicle does not start, workshop does not find faults

Hello, our Scenic 2 (Bj 2007) makes life difficult for us. -much text- I hope that someone here can give at least tips or has an idea. About 3-4 weeks ago we were at the TÜV and after that the problem or a long illness broke out probably definitely. The engine does not start. The starter orils continuously, the car does not work. Workshop arrived him and after many attempts he went on. The spark plugs were replaced. The car jumped on it as before. 2 days e no longer later. Important at this point: It is not a reliable start. If you start the vehicle then you have to tap the accelerator pedal. If you don’t, it goes out 50% again (only in the cold start). If you tap it briefly, it purrs like a kitten. We have now been doing this for about 1 year. He went on instantaneously once, once he has nailed 2-3 seconds. However, he was always at the first attempt. Again at Renault called and “battery” as diagnosis. The starter didn’t work either. Called again “Remote diagnosis not possible, bring by” Our free workshop finally picked him up and gave us a devastating answer today: “We can’t find the problem”. They had charged the battery for a short time, which he went on for a short time, but not again after that. So it was a “happy jumper” over the last week and felt 100 start attempts he went on twice. But immediately after less than 1sec w The error memory last week was empty. It was already read out after it was already fetched. Still short basic data that comes to mind spontaneously: Since this day it can no longer be started by brake/start button, but only by clutch. If you try it with the brake is always “put in empty run”. An error message that we did not know before. I don’t know if this is related. I just wanted to mention it. I read something about the OT very often. Giver. Is that appropriate? Or are there other things? I had not been able to find it myself or was it too anxious to break something.