As someone who also tired PvP with Mace wind burst enchant, this is completely true. Matter of fact the Wind Burst 3 effect is almost non-existent when diving onto opponents using elytra. You also take fall damage sometimes even when you successfully Mace Smash your opponent.
Sorry for the confusion. But everything I wrote as “broken” or “does not work” is not because I thought it was broken as my own perspective. But because it actually does not work. I don't have a PC to compare it to how it works in Java Edition and Minecraft Bedrock Edition does not have any option to revert back to previous update. I have been using the Mace ever since it came out, so let me explain how the Wind Burst enchant and Wind Charge did work before 1.21.70.
Before the update Wind Burst 1 was enough to use in PvP as Wind Burst 2 & 3 would launch you way up (like 18-22 blocks) which would give your opponent more time to react and evade the attack. However as you can see in the video I am using Wind Burst 3 and its barely launching me and in the SlamAttack you can clearly see the Wind Burst 3 did nothing to give me any upward moment.
Now about the Wind Charge and why its not working properly. I could have uploaded an Video demonstration of Wind Charge not being able to launch you upwards when the player was wearing Netherite Armor. I am sorry about it, I will take care about it the next time. Basically before 1.21.70 you were easily able to climb walls upto 8 blocks high even when the player was wearing Netherite Armor, and that is beyond it mathematical limit. But after the update trying to climb walls high as 6.5 blocks is very difficult and 7 blocks is impossible I did use over 4 stacks of Wind Charge and not even once I was able to climb over 7 blocks high.
Anyway this is all I have to say. I hope this explanation is enough to understand. Sorry for breaking the Guidelines of Reporting a bug. I will take care from next time. And about how to recreate the bug just do what I did in the video. Since I play in mobile you can see all my movement and action button. And sorry the trouble that I may have caused.