I've recently been scammed out of my money investing in Atomic Wallet so I'm skeptical about investing.
As for Locked staking on Binance, it actually offers a higher APY than Flixable, but your assets must be locked until a fixed date and time, so if you need to redeem funds early due to an emergency before the specified redemption date, you will lose all earned or accrued rewards. Also, the redemption process of your assets may be delayed for more than 72 hours in some unexpected cases. Also, the APY rate can change, as it is an estimated and variable rate. If you are satisfied with what I mentioned, you can move forward. Like the rest of the members here, my opinions are neither the best CEX platforms nor the best for depositing large amounts of money into them, but the decision is up to you in the end.
Check out these sources: [1] - [2]