Thank you for these suggestions. I have reached out to KnowBe4 and Airtame. I've provided HAR files to both support teams and fiddler captures. I have gone over the Client_IDs, and I've set them to trusted.
This is a terrible idea, but I honestly went into allow ALL third-party apps for more than 24 hours to see if that would resolve the issue, and it didn't work for any of the apps on the list. Still receiving the same errors. Replying here because I went to the companies and escalated the cases, and I have cases open with Google about this, too. Google keeps on telling us its the third-party, but again @gmail.com accounts can authenticate just fine.
The strange thing is that PearDeck, which we actually pay a subsription for and have a data privacy agreement, has a screen indicating that Google is having issues with Login.
Thanks for the suggestions. Really feeling helpless and at a loss.
