Thank you for getting back to me @Debbie Deland. I just want to help as much as I can based on my experience and knowledge, and I really appreciate your patience while we work through this together.
Just to clarify, you are still using Classic Outlook. My earlier point was simply that the first Tasks view in your screenshot appears to be the Microsoft To Do interface that's built into Classic Outlook, whereas Apps > Tasks opens the separate, traditional Outlook Tasks module. I just wanted to clarify that distinction so we're looking in the correct location and talking about the same task experience within Outlook.
From your latest update, am I understanding correctly that when you open Apps > Tasks, you can find some of the tasks that you originally mentioned as missing, just not all of them?
Another question that may help narrow this down: do you have multiple email accounts or mailboxes configured in Classic Outlook?
The reason I ask is that the presence of folders such as "Tasks (This computer only)" typically suggests that at least one account may be configured as IMAP or POP. In that configuration, tasks can be stored locally in Outlook rather than synchronized to Microsoft To Do or Outlook on the web. If that's the case, the missing tasks may have been associated with that specific account or its local Outlook data file.
Could you please check the following: File > Account Settings > Account Settings > Email then look at the Type column for each account and let me know whether any of them show IMAP/POP.
That information may give us an important clue as to where the missing tasks were originally stored and whether they might still exist in a local Outlook data file.
I sincerely hope you'll continue to respond when your schedule allows. I'll do my best to keep thinking through the issue with you and see if there are any other avenues worth exploring to help recover the missing tasks.