two problems on my new music hall dac 25.2

I just received my brand new music hall dac 25.2. This is my first dac and I really had high expectation on it. However, after 5 minutes of playing, I found two problems.
1. The headphone amp has buzz noise. You can hear it clearly when you turn volume down. At the same time, I tried the headphone plug of my 5 years old receiver, it is clean, quite.
I knew the headphone amp of this dac is so so before I bought it, but this noise is unacceptable.

2. This dac has a src button to toggle between the different sample rates: Lock (44.1KHz), 96KHz and 192KHz. There are three LED indicators for each selection. The problem is the indicator of Lock is always on. The combination is Lock on, Lock and 96K on, or Lock and 192K on. I am confused if it is really functional in choosing different sample rate.

Could other users help me to check your dac if it has the same issue ? Thank you very much! Now I am really upset.
Did it not come with directions? and if there is a buzz in the headphone jack maybe you need to send it back or call the company.
The buzz is most likely a defect. Exchange it. The "Lock" light should always be on when locked on a signal. If only the lock light is on, it's 44.1. It's just a dual purpose indicator.
It comes with a simple manual. No much information.
Based on what Rooski said, indiactor should work fine. However, Rooski, did you hear any difference between toggling different sampling rates? For me, Lock and 192K are the same, and there is a subtle difference between 96K and others.

Rooski, I just saw a picture of this dac on gon. There is only 192K LED on without Lock on. Confused again.