.... When the stock market decline, treasuries are the only asset class that rises. I am fully aware of this. Therefore I invest in 100% treasuries since this gain during the recession "should" offset any inflationary losses.
There is no rule or law that says T's will rise when stocks decline.
Quoting Gundlach in 2018:
Finally, Gundlach said that while not imminent he expects a recession in the next 2 years. Here, he made another interesting observation: he said that in the next recession we won’t see a bid for safety out of stocks and into bonds. In other words “we won’t see a bond market rally.”