Keyboard irratic behavior

I have a mid 2014 13" Macbook pro, I did buy it second hand a few weeks ago.

When I type on the keyboard, a few letters will type, and then the cursor backs up, or highlights the entire word or sentence I have typed. If i type carefully, and hit the right arrow after each letter, I can type a sentence. But that is time consuming as you could imagine. Other times I type, seems to refresh on certain key, like hitting F5. Most of the time it jumps around, and backs up on any keys that I type on.

I erased the HDD, and reinstalled iOS now I am running Catalina. Problem was there prior, and still exists. I currently have an external Keyboard and it types normal using it.

Since I have a fresh install, I don't think its software, I assume its hardware.

Anyone have this type of issue before?