Kia Optima SXL starting issues

Hi everyone. I recently purchased a used
2013 Kia Optima SXL with low miles. It didn’t
take long for it to have these starting issues.
Essentially what’s happening is I’m using the
push start and the car will crank but not turn
over. It will eventually start after maybe the
3rd try or so. At first i thought it was me
because they said it was user error. I tried
every combination you can imagine with
pressing the brake hard or light and holding
the button and just pressing the bottom. It
doesn’t seem to matter. Simultaneously it
stalled like 3 times which the last time it
popped a code which i thought was great.
They said it had something to do with the
actuator and replaced the throttle body which
they said should fix both issues. It hasn’t
stalled which is good but the starting is still
an issue. I took it to a different mechanic and
they couldn’t figure it out and decided maybe
to reset the computer/system. As soon as i
get home and go back out the problem is
back. The biggest issue is that it’s not all the
time and they can’t recreate it. It’s really
random. Has this happened to anyone or can
anyone help me shed light on the issue? Any
help would be amazing i really like the car!!!