VXOC Astra-J/GTC

Hi all,

I own an astra J 1.4 turbo (A14NET, bifuel, 40XXX km) and having some intermittent starting problems for a few weeks now. The problem is an extended cranking time, altough it doesn't always occur. Sometimes it starts up perfectly fine from the first crank, sometimes it coughs into life and sometimes it takes 5-6 cranks to start. Ones started up, it runs perfectly.
Already checked fuel pressures (perfect, no big drops), plugs are fine as well (changed 8 months ago). Fuel pressure regulator is fine as well.
Thinking it could be following things:
Coil pack or Camshaft/crankshaft position sensor. Is there anyone who what this issue as well? The weird thing is that it's intermittent, which makes me believe that it's no CPS. No fault codes stored as well.

Anyone who has an idea how to test/diagnose this or what could be the problem? Car is services regularly (every 10k km) and runs fine otherwise.
Many thanks,
Elias

Hows the battery? I know with mine if low it takes longer to crank over could be worth a test.

I think it's okay, but not really sure how i can measure that? It's still the original battery (from 2013). Voltage goed from 12.0-12.4 when not being charged to 14+ when charging. Charging is not continious when driving, noticed alternator sometimes doenst charge. Does it have an electronic clutch and only engages when voltage drops below certain level?