Using sequence in SELECT works fine whereas the same SELECT query used in INSERT/SELECT results in "The statement references the following sequence more than once" error. This happens even though the SELECT in question returns exactly 1 row of data.
The Reference Manual states 1. " NEXT VALUE FOR expression may occur in the following places: SELECT statement: As part of the expression defining a returned column in a SELECT list" and 2. " NEXT VALUE expression may not appear in any of these situations: CASE expression, WHERE clause,
ORDER BY clause, Aggregate expression, ROW_NUMBER function, DISTINCT select list".
Nowhere a restriction on INSERT/SELECT is mentioned. Additionally, other databases (i.e. Oracle) support use of sequences in INSERT/SELECT.
Therefore, I consider it a bug.