Note Heads of Different Voices Overwrite Each Other (F & G)

A pair of note heads on an adjacent line and space, such as F and G, typically are put on opposite sides of the stem for clarity. Here's what I did:

1. On a treble clef staff, enter consecutive eighth notes on G in the first voice. That works OK, stems up, heads to the left

2. Enter a second voice quarter note simultaneous with the first G, on F. Again OK, stem down head right, stem in line with the eighth note G's stem.

3. Enter a B below (under a first ledger line), continuing the second voice quarter note chord. Here's where it goes wrong: The B head goes in vertically aligned with the original G, But the quarter note stem pops over to the wrong side of the heads, and the F head pops over in line with the other two heads, overwriting the lower part of the G head.

It sounds like maybe the two voices don't listen to each other.... Is there a fix for this?

-- J.S.