While update the pre-release 3, the bottom face changed after this model.
cactus model 1: has no bottom face
cactus model 2: slightly changes to flat block
cactus model 3: normal cacti
cactus model 4 nether update first release: still no bottom face
cactus model 5 nether update: slightly changes and the top texture is slightly darker
cactus model 6 nether update pre-release: no dirt; cacti changes bottom and top face
Thank you for your report!
However, we are already tracking this issue, and this report is a Duplicate of MC-188534, which is a report that has not been resolved yet.
If you want, you can upvote the parent ticket, and enable watching to receive any updates about it - if you believe you have any information that may be important for this issue, please leave a comment on the parent. Please also use the search function in the future to prevent duplicate reports.
Quick Links:
📓 Issue Guidelines – 🛠 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki
💬 Mojira Subreddit – 💬 Mojira Discord