Thanks for the additional information. It’s definitely not a known issue. I answer a lot of the camera questions in the community and I don’t recall more than one or two other posts asking about this. Considering there are millions of 16 Pro and Pro Max iPhones in use around the world, if it were a bug or other defect there would be a lot more inquiries.
I just grabbed my wife’s 16 Pro Max that’s on 26.2.1 also and it recorded several time lapses to the Camera Roll (now called Library).
My best advice would be to upgrade to iOS 26.3 that was released almost 2 weeks ago. Apple seems to have resolved many issues previously reported by community members.
Is this a one off experience or no time lapses save to your camera roll? I know you said you have plenty of storage, but exactly how much is plenty?