Apt-Pinning Preferences ignored when Ign InRelease Files

[entr0py <3n7r0py1@gmail.com>]

I have a 3rd Party Repository added to apt sources, pinned via apt preferences so that
Stable = 800, Testing = -1

apt-cache policy shows that this is the case.
Several months of usage has also confirmed that it is working as intended.

Recently, I ran apt-get update while my network connection was down. All of the InRelease/Release files were Ign. Connectivity was restored while update was in progress. update completed successfully with no errors/warnings.

When I ran dist-ugprade, all of the packages from Testing were proposed as candidates. apt-cache policy showed that all repositories were pinned to 500. policy also revealed that the 3rd Party Repositories were missing all of their Release "tags", ie origin, codename, etc. which is why their pins were ignored.

When update was run again, the Release files were downloaded and upgrade showed no new packages.

1. Why weren't the Release tags from the previous successful authenticated download used?
2. Why weren't there any messages indicating that the Release files were not complete?
3. Is there any way to enforce that Release files must be Hit or downloaded and not Ign?

Thanks!