[Outlook App] Junk Email folder keeps having junk nonstop

The difference between Outlook on the web and the desktop app is important: it suggests the mailbox may be correct on the server while the desktop client is displaying a local synchronization or view problem. Do not assume every rising Junk count represents newly delivered mail. First note whether the message list itself duplicates, whether the count changes after Send/Receive, and whether Outlook’s Sync Issues folder records an error. Confirm whether this is classic Outlook or new Outlook, because Cached Exchange Mode applies only to classic Outlook. For a Microsoft 365 or Exchange mailbox in classic Outlook, verify that Cached Exchange Mode is enabled, restart Outlook, and let the folder finish synchronizing before repeatedly emptying it. If it continues, capture the exact account type, Outlook version, folder count, and any Sync Issues error for Microsoft support. Avoid opening or interacting with suspicious messages merely to test the behavior; use Outlook on the web temporarily if it remains accurate.