In trying to make sure no duplicate entries ended up in a list I discovered that the “Does List x Contain” method block is case-sensitive. (illustrated in screenshot)
As a workaround, setting both the input value to be tested as well as all saved values to Title Case is a reasonable way to achieve the desired results for this particular case, but it would likely be annoying for anyone who may be storing case-insensitive (displayable) data in a List while trying to avoid duplicates.
Meanwhile I suggest a new feature on the “Does List x Contain” method block to allow the choice of case-sensitive or case-insensitive matching.
I hope this helps someone!