I believe this affects the Android TV version as well, but was recorded on an Amazon Fire TV.
The bug is if you go down through the guide and find a show that is less than 30 minutes and then scroll back up, it highlights the last time slot on that channel. When scrolling down it selects the show properly It only seems to happen when going up in the guide.
Here is a video of the behavior: https://imgur.com/a/uOOLlAK
Watch channel number 6763 in this instance. This is not limited to this channel, it happens to any channel that has a show less than 30 minutes long.
I noticed this behavior before and after the 3.0 update.