This is going to be a longer post than I intended. There's no solution here for this issue, or specific advice for troubleshooting it, so please feel free to skip it.
The most important, productive piece of advice you'll get from any discussion in this forum will be to make sure you contact Apple Support. While this user forum is a great place to discuss your experiences or vent your frustrations, it's important — to everyone sharing your issue — that you also make actual Apple techs aware of what you're experiencing, so they can research and resolve it.
If you're having a problem that you need fixed immediately, in addition to posting about it here you should install the official Apple Support app on your phone and use it to report your issue; the app will direct you to the best place to find help, possibly in person, possibly via phone support, etc. You could also just go directly to Fortunately, iPhone 16 devices are new and still fully covered by AppleCare+, so you're likely to get a response that's quick, friendly, and free.
It's important to be aware, tho', that searches on Apple Support's official website, support.apple.com, will often direct users to these discussions as well as to official support articles; that might seem unusual, but it's because of Apple users' long history of discovering workarounds and sharing them here.
We're still waiting for that breakthrough in this thread, obviously — but when it arrives it'll come from someone who ignored posts suggesting their problem doesn't/can't possibly exist, or that if it exists, it must be an easily-resolved PICNIC issue.
And feel free to disregard statements that there can be no problem with software like iOS unless it affects all users — it's obviously false, unhelpful, and discourages you from sharing information about what does, in fact, seem like it could be unusual behavior. It's the opposite of what these discussions are meant for.
(There are, naturally, myriad reasons why some users experience issues with a software or software product while others don't. Apple is better about quality than most, and by a wide margin — but not perfect, and many popular, successful Apple products have at times experienced problems that were prickly to troubleshoot *precisely because* they only affected a small subset of use cases. If you've owned or used many Apple products over the past 40 years, you probably recall a few.)
The good news is, Apple is also better than most at solving even the prickliest of these issues, eventually; it just takes time. In the meanwhile, please simultaneously use Apple Support and post in this forum about what you've done to troubleshoot this problem, whether on your own or with Apple Support's help — and don't let anyone deter you from doing that. Even just venting your frustration here is fine; in fact, it's probably better to do that here than to Apple Support techs, as long as you're using both.
Apple users have a proven track record of poking around until they find something that works, and this forum has a proven track record as the place those workarounds are shared. Please don't be discouraged by unproductive posts implying that since not everyone shares your problems, the problem must be you.