I was transporting villagers in my survival world by boats when I realized that every time I get out of my boat, I punch the villager riding with me. After I tested this issue more I found that you can also place blocks upon going in or out of the boat

How to Reproduce I have split controls turned on
Placing Blocks:
1. Have a block at hand
2. Tap on Ride Boat button
3. If it is on reaching distance, you'll be able to place a block
4. Tap on Leave Boat button
5. Same as number 3

Punching mobs:
1. Make sure you have a mob riding with you on the boat
2. Face the split control pointer as level as possible
3. Tap Leave Boat button
4. When you get out of the boat, you'll be able to punch that mob