Потому что "member" является ключевым словом JPQL.
https://docs.oracle.com/html/E13946_04/ejb3_langref.html#ejb3_langref_collection_member
QueryDsl содержит их список и экранирует их, добавляя числовой суффикс:
http://www.querydsl.com/static/querydsl/4.1.4/apidocs/index.html?com/querydsl/codegen/Keywords.html
public static final Collection<String> JPA = ImmutableList.of(
"ABS","ALL","AND","ANY","AS","ASC","AVG","BETWEEN",
"BIT_LENGTH[51]","BOTH","BY","CASE","CHAR_LENGTH",
"CHARACTER_LENGTH","CLASS",
"COALESCE","CONCAT","COUNT","CURRENT_DATE","CURRENT_TIME",
"CURRENT_TIMESTAMP",
"DELETE","DESC","DISTINCT","ELSE","EMPTY","END","ENTRY",
"ESCAPE","EXISTS","FALSE","FETCH",
"FROM","GROUP","HAVING","IN","INDEX","INNER","IS","JOIN",
"KEY","LEADING","LEFT","LENGTH","LIKE",
"LOCATE","LOWER","MAX","MEMBER","MIN","MOD","NEW","NOT",
"NULL","NULLIF","OBJECT","OF","OR",
"ORDER","OUTER","POSITION","SELECT","SET","SIZE","SOME",
"SQRT","SUBSTRING","SUM","THEN",
"TRAILING","TRIM","TRUE","TYPE","UNKNOWN","UPDATE","UPPER",
"VALUE","WHEN","WHERE");
Почему это проблема, учитывая, что вам никогда не нужно ссылаться на это в своем коде?