Maybe you bought links too soon? 60 days I think it's not too old to buy backlinks.Well, everyone who thought a sandbox was wrong, this was indeed a penalty!
After a month, I decided to change the domain and set 301 redirects from all URLs to the new domain. Everything went well for a few days, and I was happy to recover and see the growth.
Then yesterday another penalty, hell noooo! The 301 redirects took juice from the existing backlinks as well. But some of those links were probably toxic, which was the principal reason for the penalty. Interesting thing to say, I bought all my links on BHW marketplace. When checked all links seemed fine but I might have missed one.
Morality of this story: if you aren't careful even the smallest toxic link can destroy your website nowadays. Deal carefully when you order something read reviews, and write reviews too so people don't get deceived and know what they order.
I don't know, just my opinion