LTspice .meas command: unexpected single fail in step when the rest passes ok
Solution from ADI Engineer Zone:
https://ez.analog.com/design-tools-and-calculators/f/q-a/163106/ltspice-meas-command-unexpected-single-fail-in-step-when-the-rest-passes-ok


  Hello Marcin,
  
  I have seen this kind of problem sometimes. The solution is very
  simple. Just compare with a smaller value. Often a factor of 1e.9 will
  be sufficient as in your case.
  
  .meas AC f0 WHEN MAG(V(Out))=x*(1-1n)
  
  Just one tip for better readability of the reaults with magnitude
  instead of dB.
  
  .options meascplxfmt=polar
  
  Helmut