Hi Zenrain,thanks a lot for that prompt reply.I followed your suggestions and re-indexed both indexes. Then I realized that I must have come across with only a "special case" within PBs normal behaviour. Yes, quick search seems to be working again, but not reliably. The issue I was reporting relates to a special thought that has 5 words in it (all synonyms of the first one).
Every time I typed in the first 1 or 2 letters the thought in cuestion DID show up but disappeared again after adding another character as is if this additional character was NOT part of the word, but of course it was. In order to find out the reason I started changing the word order. Only after a third or fourth rearrangement the thought showed up as expected.
Good to see that you could reproduce this issue ...
IMO it is a pretty serious bug since now we never now whether or not a thought is part of the Brain.