Definition of something is up in English:

something is up

phrase

informal
  • Something unusual or undesirable is happening.

    • ‘If girls and boys are getting higher grades for doing old papers that were scoring two or three grades lower last decade, something is up.’
    • ‘Upon landing in Dorval, I counted 18 hours without sleep, so when my phone rang wildly I knew something was up.’
    • ‘I don't know why, but I have a feeling that something's up.’