Savings APR reduction normal?

Guys, Is this normal or does this usually happens?

So, I checked my Binance app to check my USDT I stored in the Savings to see how far profit I have gotten, I realised that the APR has reduced to 7.5%. I thought maybe is a general issue, then I went to my Bitget to check as I also have some USDT stored in their Flexible savings and realised is still at 15%

I want to know if this happens occasionally or there’s a reason for the sudden reduction. Mind you, this is my first time using USDT savings to store my USDT. You know, I need the safest way I can keep my usdt and it will generate some profit because I need to buy some coins when market is in deep and not risking them all in trading right now.