Known cases of block-withholding attacks At the moment I am doing a course about Bitcoin. The topic of the last session was the block-withholding attack and the course (being from 2014) claimed that there are no known attacks so far.
Is block-withholding a strategy used by mining pools in 2021? If so, where can I find evidence to back that up?
According to this article from 2016 it seems Slush pool had noticed or someone reported issues related to block withholding:
http://organofcorti.blogspot.com/2016/02/detecting-unintentional-block.html
Not sure if it works in 2021 and which mining pools are affected.
While researching about OP_CTV I read about trustless coordination free mining pools: https://utxos.org/uses/miningpools/ so we can assume OP_CTV fixes this however it's not activated yet.

This type of mining pool has no trusted operator and requires no coordination. This eliminates various types of mining pool attacks, such as block witholding.