Kia Ceed GT MY22 Tyre pressure for series summer bikes

Hi, wanted to ask in the round, who drives the new Ceed GT with the standard bikes. What are you there for a tire pressure on it? 225/40 R18 92y tires on it. So dealer has 2.8 bar on it for me and after a few kilometers shows me onboard computer 3.0 bar. Is that too much? Because I find it quite hard with bumps. In the door stands 2.4 bar, which comes to me again little. With how much bar do you drive around? Have now reduced times at the tank and have now 2.7-2. Eight bar according to the on-board computer in it.