Rapid Battery Health Decline on MacBook

Hi, I have a MacBook Air M3 that I bought about six or seven months ago.

During this time, it's gone through 134 charge cycles in total.

I've always charged it between 20% and 80%, and I haven’t used it heavily—just regular daily usage like browsing the web, watching movies, and things like that.

Despite this light usage and only 134 cycles, the battery health has already dropped to 88%!

Would this be covered under warranty?

And would Apple consider this as a potential defect and possibly replace the laptop?

I also ran Apple’s hardware diagnostics, but it didn’t show any issues. The checker app said the device is in perfect condition, which is really strange to me!