I have Nokia DC-801 car charger for my Nokia 8.
Most of the times the charging doesn't start before I reboot the phone.
After using DC-801 the phone doesn't charge on normal USB charger, the reboot is needed in this scenario also.
In short - both chargers work with the phone, but not without rebooting.
Seems like some sort of software problem.
Is there a way for me to fix this?
It sounds like a faulty charger or phone. I suggest you contact HMD directly using the support app.