Messages App: New and old conversations are coming in muted and then reverting back to muted after fixing it

iOS 16.5.1/iPhone XS Max 64 GB...fully updated. All new messages are received muted, contrary to all system settings being appropriately applied and double-checked. The same conversations also have Hide Alerts applied globally to the sending contact(s) on my phone. Even after addressing this problem, which I did by turning off Hide Alerts and unmuting the conversation, the conversation mutes and hides alerts again, without any user interaction. I have already performed all suggested attempts at mitigation, with no resolution of the issue (Check Settings; Check current software version; check DND [oops, it's called Focus, now] which I have never, ever used; I even performed a full Reset All Settings (which did not work and took forever to get through all the helpful. I do not use any third-party messaging apps. Research suggests that this is an issue others have faced under various iOS releases, with no resolution, or even answers as to cause. I am not going to pay to join the Developer program just to file a bug report, nor am I going to buy Apple Care so that I can speak to Support. Please let me know when you are going to fix this issue, or actual working steps to mitigation.