Performing Automatic Upgrade installer warns about phantom component

[1Gunn1]

I am modifying a Basic MSI to include an upgrade for our previous release. I have used the Media->Upgrades section to add an Automatic Upgrade Item and have pointed to my previous installer. 

I get a warning when building the installer saying it will perform a MINOR upgrade, but then yelling at me that a component is missing from the newest version of your setup and that a major upgrade must be performed. Here is the exact lines from the build output:

ISDEV : warning -6487: If you intend to distribute this upgrade as a patch, you should author the 'Patch Optimization' setting on the Advanced Settings panel of the Release Wizard.
Media table successfully built
Performing Upgrading and Patching Validation
Val0003: This setup will perform a MINOR upgrade of the referenced previous setup c:\users\t~1.nre\appdata\local\temp\afe0\filename release 2021.1.msi
ISDEV : error Val0006: The Component '_AB7038D8CC958FA437E073E95FD47C42' identified by ComponentID '{AB7038D8-8CC9-58FA-437E-073E95FD47C4}' is missing from the newest version of your setup. You can not delete components and still do a minor/small upgrade. You must perform a major upgrade. c:\users\t~1.nre\appdata\local\temp\afe0\filename release 2021.1.msi
ISDEV : warning Val0015: The CreateFolder table contains new content. Therefore, if you are packaging this upgrade as a patch, you will not be able to make it an uninstallable patch. c:\users\t~1.nre\appdata\local\temp\afe0\filename release 2021.1.msi

Two questions:

1) Why did the "automatic upgrade" decide to perform a MINOR upgrade, but then yell at me that I must perform a major upgrade??

2) The component is references...I could not find it in my previous installer project file, nor this one. What is this? Where is it coming from? And why doesn't it give me the name of the component I created, instead of just the GUID and some other form of the GUID? If it gave me the name, I might be better able to recognize it. But to be clear, a component with this GUID does not exist in my previous installer that I'm creating the upgrade against. 

And in regards to the Warning, the 'CreateTable' does NOT contain any differences between the current .ism and the previous .ism used to create the previous installer. So I have no clue why it is reporting that either!

Any help on any of this would be appreciated.

[1Gunn1]

A little more info...

I ran into this error again while developing the installer further,

"ISDEV : error Val0006: The Component '<blah>' identified by ComponentID '{<GUID>}' is missing from the newest version of your setup. You can not delete components and still do a minor/small upgrade" 

The interesting thing this time is that it actually mentioned the user-friendly name of my component (where the <blah> is above) and then also listed the GUID. This was my fault, so I fixed it. 

So...this phantom component, which lists the GUID but in an alternate format (leading underscore, dashes removed) is definitely not something I authored. What the heck is it?!

I even went back through several years worth of previous .ism in our source control app and no where could I find this GUID anywhere!

Interestingly, this "error" still builds a setup.exe...

Driving me crazy... 😠