As a follow-up to this post, I wanted to document that I received the replacement speaker in the mail at the beginning of the week. That evening I switched the batteries from my current unit to the new one and was experiencing the same exact problem. At that point it occurred to me that maybe the batteries were to blame, so I switched them out for new ones and the speaker worked fine, which means the original speaker probably wasn’t broken to begin with (didn’t even think to put new batteries in that one to check). I’m surprised the person at Philips didn’t ask about this. Surely this isn’t the first time they’ve heard of such an issue.
I’m still going to ship back my original unit to them via FedEx (pre-paid postage was included), and despite how very accommodating they’ve been I don’t think I’d buy another portable speaker again due to how quickly it eats through batteries. I barely used my original unit before having issues so it doesn’t seem like a very cost-effective solution particularly because it uses AAA batteries and I only have a charger and rechargeable batteries in AA.