You can also set your osTicket Log Level (Admin Panel > Settings > System) to DEBUG, wait for the cron to run, and check your Admin Panel > Dashboard > System Logs for any related errors.
Do you have any filters that reject tickets or do you use the system banlist at all (Admin Panel > Emails > Banlist)?
My last comment I promise 😅 The preferred method is to configure a cron job to automatically poll the mailbox every X minutes. This will keep the token refreshed consistently and fetch mail and send alerts even when no one is logged in. With this in mind I noticed you had Fetch on auto-cron and Email Fetching enabled which is not ideal. This can cause issues so once you get cron working uncheck the box for Fetch on auto-cron (leave Email Fetching Enabled however).