Always choose those stable coin which is backed with fiat and stay away from those Stable coins which are backet with algorithm. We already seen ust and Dei crash.
In my view most trusted stable coins are Usdc,Dai and Busd. These stable coins are backed with fiat with strong Support by Etherium and Binance respectively. Government of England also looking to legalize Usdc and it's good for this Stable coin.
We have to be careful when choosing a stable coin that is a shitcoin, so don't fully believe in a stable coin because its value can not always be maintained for $ 1 but it has been proven that stable coins are also part of shitcoins that can collapse at any time.
I think you are talking to the stable coins that @MFahad mentioned first in his post. Haven't heard about dei but it sounds like a clone version of the dai stable coin. By its name we can already say that it was a shitcoin. A fake stable coin try to imitate an already established stable coin in the market. The second one is ust.
Many are fooled with this stable coin. They never thought that this ust will collapse because it was related to terra luna, which was also making a name before it turned out bad. The stable coins named as usdc, busd and dai are already proven and tested to be safe because they are backed by legit companies that are already been here for years.