Working on the rest of your suggestions, thank you!
But first to answer your Windows Update question, yes, the last update before this problem began was installed two days earlier: https://support.microsoft.com/en-us/topic/january-24-2026-kb5078127-os-builds-26200-7628-and-26100-7628-out-of-band-cf5777f6-bb4e-4adb-b9cd-2b64df577491
