When I navigate the menu on my Sling App on Apple TV 4k, the menu tends to move 2 rows at a time. I can cut off the signal using my hand to get it to move one row at a time. If I change the duration from default to some other number, then the timing of the button presses becomes critical. Any ideas?

What IR codes are you using? Where did you get them? ;-) Are these codes you learned or did they come from my post.

Note that if you install the Amazon Prime app, left and right also do this.

I had tried the codes you posted in a different thread but they had the same problem. I was able to fix the problem by re-learning from the original apple TV remote, being sure to press the apple remote button quickly. I went ahead and re-learned right and left as well.

How did you re-learn from an AppleTV 4K remote? That remote is bluetooth AFAIK. AFAIK, the remote only sends IR for the Volume Up/Down which needs to be transmitted to the TV.