Unknown function 'exists'

I am inspecting yFiles foe neo4j and realised exists queries to Neo4J does not work. I googled and see stackflow link like this.

MATCH (n),(f)
RETURN n.username AS username,f.name AS name, exists((n)-[:WATCHLISTED]->(f)) AS watchlisted

returns

Neo.ClientError.Statement.SyntaxError: Unknown function 'exists' (line 2, column 47 (offset: 68))
"RETURN n.username AS username,f.name AS name, exists((n)-[:WATCHLISTED]->(f)) AS watchlist"

If I write uppercase EXISTS. Query works well. This is most probably due to os charset. I am using windows 10 and ubuntu 18 with Turkish charset and regional settings. In both os the problem is the same. Also problem appears in desktop and browsers. yFiles uses bolt connection and exists queries returns the same error with lowercase.

Ubuntu I changed regional settings to US. Problem disappeared. Because in Turkish charset uppercase(i) changes to İ character not I.

Thanks for help.