Keep in mind that in some tld’s (like .nl) the whois data actually dictates who is the legal owner of the domain. If you get into an argument with your registrar, and the whois data shows their name, you can’t take action to move it or reclaim it without their approval.
Also if you let it expire, for the cool off period, only the original owner can reactivate it, that means you can’t reactivate it through another registrar. Maybe your current registrar allows it, bit that’s a maybe.
Also don’t underestimate the fact that OP has a new phone and is trying stuff out. The screen is usually one of the biggest power drainers in phones, so it could be that it just isn’t a fair comparison. I wouldn’t be surprised if the phone is just unlocked and awake more in the first few weeks compared to a phone you’ve been used to.