The actual version sets the session parameter PLSQL_DEBUG to TRUE.
All normal (without debug) compiled plsql objects were compiled with debug!!!
an additional test:
i closed all connections and opened them again and the wrong icons are still present.
a query on the plsql settings views does not show any plsql object wiht debug.
I don't understand: how a version can set any parameter, it is just a number?
P.S, This bug may be related: