sound/strike a false note

sound a false note

To indicate or give the impression that something is wrong, disingenuous, or deceitful. I know she apologized, but it sounded a false note with me—I don't believe she meant what she said.
See also: false, note, sound

strike a false note

To indicate or give the impression that something is wrong, disingenuous, or deceitful. I know she apologized, but it struck a false note with me—I don't believe she meant what she said.
See also: false, note, strike
Farlex Dictionary of Idioms.

sound/strike a false ˈnote

seem wrong, not appropriate, etc. in a certain situation: I really thought his speech at the conference struck a false note. Instead of saying how serious the housing situation was, he was telling jokes about it.
See also: false, note, sound, strike
Farlex Partner Idioms Dictionary
See also:
  • sound a false note
  • strike a false note
  • false note
  • catch not at the shadow and lose the substance
  • take the shadow for the substance
  • ring false
  • ring true
  • ring true/false/hollow
  • swallow (something) hook, line, and sinker
  • swallow hook, line, and sinker