Motor takes longer to start

Hello together, for about a month now I realize again and again that my up takes longer to start than usual. If I turn the key, it will take 2-3s longer than before until the engine starts. This only occurs if the car was standing longer (e.g. overnight). If the car is parked and restarted after half an hour, it will start normally. It is about a BJ 2014, 69,000km with the 44kw (60hp) engine. I have the battery before c a. 6 months renewed (Bosch). The spark plugs were already new in 2018 at about 42,000km. The problem I noticed for the first time about 1 – 1.5 months ago and since then regularly. Before he jumped directly at the key turning, now he orgates for 2-3s. Has any of you ever had similar experiences? Or tips where to look? Thanks and greetings!