Killer Instinct Unavailable Content

I got Killer Instinct when it came out with GwG a few years ago and recently started playing it. However, despite having all the content that was made available at that time, I only have access to the characters that seem to be connected with the Ultra Edition.
I had thought it was perhaps a content issue, but when I started playing online with a friend who downloaded the content at the same time as me, he had access to everything, not just the limited access I seem to have.

I have confirmed that all the content is fully downloaded, including (but not limited to):

• all individual characters
• Killer Instinct Season 2 Ultra Edition Add-On
• Killer Instinct: Season 2 Combo Breaker Add-On
• Killer Instinct: Season 3 Combo Breaker
• Killer Instinct: Season 3 Ultra Edition

Between all of these sets, theoretically I should be able to play with all published characters.

I've tried uninstalling and reinstalling the game twice, both reinstalling everything in one go and individually selecting add-ons to see if the order of installation impacted anything.

I've checked the Xbox Store to make sure they were listed as being purchased, and they are.

I've also uninstalled and reinstalled my gamer profile from my system to ensure that everything has been synched.

Checking these posts, it looks like other gamers have had similar issues, but I have yet to find a solution that fully resolved my situation. Please let me know what else can be tried, as I would like to have access to all the content that I've downloaded.

:)