Why is my car stuck in limp mode after replacing alternator and battery

What is your question?

I was driving home last night, and the car was running on residential roads with no issue. I tried to accelerate from 45 mph to highway speed going up a highway on ramp, but the engine revved a little then lost all power, and all lights came on the dash. I suspected the alternator, because the battery was < 7 days old. I have replaced the alternator, and trickle charged the battery back to full. Car now turns over easily and idles, but when I try to drive it, it is stuck in limp mode and will not go over 20 mph, and then backs off speed and power from there. There are no codes or Check Engine lights to indicate an issue.

How long has your 2016 Kia Soul had this problem?

A day