The receiver slot is appended to the current block, but the expression stack
was only flushed inside the per-parameter loop - which the increment operators,
taking no parameters, never enter. A side effect still pending on the stack was
then emitted after the receiver read it should precede, so the increment
applied to a stale value of the field it targets.
Assisted-by: Claude:claude-opus-5:Claude Code
Siegfried Pammer