Hello everyone. Now I have also encountered this pain.
For my project I needed a couple of thousand tBTC testnet4. I went the classic way, rented an ASIC. And then I came across the above descriptions not only in this topic.
Maybe it is worth sharing an option on how to repeat CPU mining. I am ready to launch 10-50 of nodes and pools to cut off the ability of this individual to mine so much and make a faucet for free distribution of coins.
I am very sad about what is happening because of such a "bug"