WF find fails with single quote [**followed by underscore]

[windymilla]

Word Frequency/Diacritics finds
Armesünderblum but clicking on the word doesn't find it in the text where it is die Armesünderblum'

NTS: Don't break apostrophe handling, e.g. dog & dog's

[windymilla]

Unable to reproduce in 2.0.22

[windymilla]

Updated example

suicide's grave, _die Armesünderblum'_, the poor-sinner's-flower.