Some of the notes don't render the full note value and just show up as a dot, is this normal?
there's a box for each track labelled "staccato", uncheck it if it is checked and they should display their length. if thats not the problem then i have no idea why it happens but one other person has reported this, when a note ends and starts at the same time it can make the second note end early. not ideal but a fix for it if this is ur problem is to shorten the first one so they don't "overlap"