[EC900]

I’d try another battery that has a confirmed 14.6 v. Recheck the battery posts for cleaning and ensuring they’re tight.

Any background on the cars usage?
Has it sat in storage maybe getting driven only once every few months ? Do you use a battery tender during storage?
Depress clutch pedal before starting too. then in gear, could be seized and rusted to flywheel if stored in damp conditions long time.

The ignition switch contacts can be dirty, tarnished or a bit corroded from no use.
Try rotating key on-off-run a few times to activate the switch, which the electrical portion are known to go bad and problematic and keep in mind that the ignition lockout isn’t interfering with turning the key and loosen any tension that may be on the steering wheel.