I'm on 1.21.1
Fabric version 0.16.10
Mod version 3.2.8

I have used diamonds on my armor with a random trim to test it out as I wanted to see if I could insta mine deepslate with a haste 2 beacon but the effect just doesn't work and doesn't appear anywhere. I don't see anywhere where it says how to activate it if it needs to be activated. I then tested it on a creative world and went into to config to make it the max speed and even that didn't change anything. I then disabled the diamond effect and restarted my game and I had the same speed so it wasn't working, but upon joining back, with the armor on, and with the diamond disabled, I got the miner's rush effect, but even with it showing I wasn't getting the boost as I had disabled the diamond effect. I do not know what it happening and why it doesnt work.