2015 KIA Optima Not Starting After Engine Recall

My car shut off while I was driving April 1, 2019.
Had it towed to the KIA dealership because they
said these engines were recalled. It took almost 3
months before I got my car back. They had to
ensure my car broke down do to engine failure,
submit documentation & pictures to KIA
headquarters and wait to receive the approval to
order the new engine. After the engine was
replaced, my car randomly didn’t start. The
dealership said I needed a new battery, so I
purchased a new battery from AutoZone and it still
was randomly not turning on. I took it back to the
KIA dealership and they said my car was not
starting sometimes because of the aftermarket
alarm on my car. The dealership recommended I
have it removed and told me about a place to have
it done at. I went to the recommended place, had
the aftermarket alarm removed and it seemed to
solve the problem THAT day. But the next day my
car wouldn’t start. I tried the brake, shift method
and that seemed to start it a few times but now my
car seems to take longer to start up. The power
works but it won’t start. Outside of the dealership
recommending I have the aftermarket alarm
removed, they don’t know what the problem is.
Any other suggestions out there on how to start
my car that has this brand new engine & battery?