We do not take any more damage with cactus
Linked issues
Comments 2
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-14303.
Please add a vote and any new information to the main ticket, which will be updated accordingly.
If you have not, you might like to make use of the search feature before making a new ticket, as it's likely that the issue has been reported already.
Quick Links:📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki
I wonder why you can’t take damage from a cactus while standing on top of it. Probably the same problem.