Difficult starting

[Cees Klumper]

Hoping for some pointers. Tried the search but could not find my symptoms.

It's a 2008 C70 with the auto-start function (turn the key briefly to the 'start' position, let go and the system is supposed to continue cranking until the engine starts running).

Frequently, when trying to start the car, the starter will engage and spin the engine, but then, before the engine can 'catch', the starter just stops spinning, even though I have the key turned to the 'start please' position. So I have to start over again, and sometimes it takes two or three tries before the starter will spin long enough for the engine to catch and start. This is annoying but, so far, it has always started in the end. I am concerned however that, at some point, it will just refuse to start altogether, also because it seems to be getting worse. I thought perhaps I was not pressing the brake pedal strong enough, but that does not seem to be the cause.

P.s. the starter was replaced with a new one by the previous owner, last year (I have the invoice for that so it seems legit).

Any pointers? I get no codes from my Icarsoft II reader. Immobilizer, loose cables, key fob battery getting weak?