Invalid issuer or Signature on Token

[danielcostalvt]

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

SharePoint Add-ins

Developer environment

None

What browser(s) / client(s) have you tested

• [ ] 💥 Internet Explorer
• [ ] 💥 Microsoft Edge
• [ ] 💥 Google Chrome
• [ ] 💥 FireFox
• [ ] 💥 Safari
• [ ] mobile (iOS/iPadOS)
• [ ] mobile (Android)
• [ ] not applicable
• [ ] other (enter in the "Additional environment details" area below)

Additional environment details

• browser version
• SPFx version
• Node.js version
• etc

Describe the bug / error

Starting this week, a few customers using my solution (without any change to the solution itself) started to get a Invalid issuer or Signature on Token

Steps to reproduce

Expected behavior

Token validation to work correctly