Thanks for the tips @mesquitebean. I tried using my phone number to recover possible accounts as you suggested, and on a browser that I rarely use to avoid cached data, but I can see only one account (with 1 email address) associated with that phone number. So that doesn't seem to explain why some products are missing in my Products page.
@mesquitebean wrote:
When their are gaps in the product years like that, it's possible that you may have more than one online account without realizing it. Here's how you can check:
You can have up to 5 accounts that use the same email address for notification purposes. A User ID may be an email address, but it doesn't have to be. It might be only part of an email address, or it can be anything at all.
To get a list of your User IDs, reset password, and recover account access, etc., you can use the tool at the link below. When using the Account Recovery tool, try using your phone number first if you can still access it. After that, if necessary, then run the tool on your email address(es) you can access.
