This was reported before (Issues with Chord Search - #12 by SilentPaaw), but I thought it might be worth splitting out into its own thread. When searching for this cadence, the first three results are perfect and the other two contain the sequence, but not at the highlighted location:
When searching without the box checked it works OK: for instance, V/V iv V7 I finds “She Loves You” with the last four chords highlighted.
I suspect it has to do with the logic for how repeated chords are handled. The “She Loves You” chords are
V vi vi64 vi vi64 vi V/V V64/V V/V V64/V V/V iv V7 I.
Removing chord extensions and inversions yields
V vi vi vi vi vi V/V V/V V/V V/V V/V iv V I.
Removing repetitions (unfortunately necessary, since people do sometimes repeat chords for rhythmic emphasis only), it becomes
V vi V/V iv V I.
And the search was for V/V iv V I, a sequence of four chords that we can now find starting at chord #3. But when the program went to bold the results, it bolded four chords starting at #3 in the original list, with inversions and repeats, so it returned V vi **vi64 vi vi64 vi** V/V etc.
A simpler example:
Thanks for details, this will be helpful in debugging. You’re correct in that the repetitions are causing the error. I’ll update this thread as we make progress.
@gmcerveny Just a friendly reminder that all of the other bugs reported here and here are still present as well. 
