I got these: BIGTREETECH Direct Anti Backlash Spring Loaded Nut Pitch 2mm Lead 4mm Elimination Gap Nut for Acme Threaded Rod Lead Screws DIY CNC 3D Printer Parts https://www.amazon.com/dp/B083JWJT8W/ref=cm_sw_r_cp_apip_7XJaywsmb84mF
Make sure you get the 4mm pitch (I’m assuming you have a newer Ender 5 plus)
Known problem with the brass nuts on the zaxis lead screws. I bought anti backlash brass nuts that took the noise away completely. I bought these ones from Amazon
I ended up getting the brass versions and they work great so far, no more noise.
I followed this guide:
https://www.youtube.com/watch?v=lBpXHWJG7aM
I got these ones from amazon:
Change over to these anti backlash nuts. I had to replace my brass nuts with these and it took away all screeching. The sound only gets worse without the replacement. Here is what I purchased https://www.amazon.com/dp/B083JWJT8W/ref=cm_sw_r_cp_apip_7XJaywsmb84mF