Created attachment 172455 [details]
screen recording of issue

SUMMARY

As I'm typing a query, results appear on the first letter entered, then disappear, then reappear. See video.

The effect appears to happen for downstream widgets like Milou as well, although it's less prominent because the widget doesn't resize when the number of results changes (I think this is maybe a bug?).

My guess is that there's a weird heuristic driving this effect, something like - if query contains less than three letters, show results that *begin* with those letters. If query contains three or more letters, show results that *contain* those letters. That sounds reasonable enough in principle, but in practice it can behave in pretty undesirable ways, as seen in the video.

Maybe a reasonable alternative heuristic would include:

  * Keeping existing results when new letters are added if those results would match under the three letter "full" check. This would get rid of the problem where a result (like System Settings in the video) disappears then reappears.
  * If less than n - some magic value - results are returned for one or two letter searches, fill in the gaps with a lower priority full text search for certain allowlisted plugins that are not research intensive.

The slightly annoying bug summary is for searchability, sorry about that.

STEPS TO REPRODUCE
1. Enable *ALL* search plugins in Plasma Search settings, to show that this isn't caused by insufficient result availability.
2. Type any query as described above (or see the video).

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.1.4
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2
Kernel Version: 6.10.3-arch1-2 (64-bit)
Graphics Platform: Wayland