Wildcard Query Search is case-sensitive

EPiServer Find 13.2.1

We have followed Joel Abrahamson's approach on WildcardQuery with EPiFind.

Though, it seems that the Wildcard Query is case-sensitive. :(

For example, if we try to search a content with Field having a value "EPiServer Developer Community", the search term "episer" or "episerver" will not return any results.

Is there any way to resolve this?

Thanks in advance!

P.S. Filter(x => x.Field.MatchCaseInsensitive()) is not an option at the moment for our case -- as we're using this for generic searches.