Do I need to keep updating my wallet address in faucets? I notice that my wallet address keeps changing and I am wondering two things:


Why does the address dynamically change?
Do I need to update the wallet address in the faucets I use in order to receive the satoshis? 


It will be a pain if I have to constantly update my wallet address in the faucets.
You're using a HD Wallet which specifically avoids reused addresses. You can of course reuse an address, so putting the same address into faucets is probably the only way to spend the low value input.

So, yes, reuse the address