Craft's control panel search function returning inconsistent results
MySQL uses a list of stopwords when performing full-text searches. As you can see, about and still are in there... At the top of the page they say:


  False hits or misses might occur for stopword lookups...


I think this is the issue here. One way to get around it in your case is to add the below in your config/general.php (docs):

'defaultSearchTermOptions' =&gt; [
    'subLeft' =&gt; true,
],


If the above helps, another thing you can try is to change the storage engine your searchindex table from MyISAM to InnoDB. That would allow you to remove what you've added in your config/general.php but would require you to have at least MySQL v5.6+.