2010 Kia sportage intermittent starting problem

I have a 2010 Sportage with 264000 km. All
maintenance done never had any major problems.
Overall a good solid car. Past 9 months on and off
when key in ignition sometimes it doesn't turn
over. Lights on as is windows work and radio. Has
a new battery as well as new alternator. After a
few minutes try again and usually starts. Have
taken to regular mechanic and they cant find the
source. Has been doing this usually every few
days. Doesn't like alot of starting and stopping if
running errands. Was suggested try new ignition
switch as well as ignitor switch as least expensive
and see if that helps. If not try replacing the
starter. Kia dealership as well cant confirm if this
is or is not the problem. Hugely frustrating cause
now just elimination of a few possibilities.
Another suggestion was fuse box? Any
suggestions out there? No longer comfortable
driving out of town or at night in case it doesn't
start. Only driving local now.