Piano roll won't play two notes at once

I don’t know if this is Cubase or the VST I am using, but I started a new project today, and tried to put in two note chord on the piano roll for a French horn. It would play the lower note for 1/4 of the beat, then switch to the higher one only. This issue also came up in my double basses. However, if I load a previous project chords play without issue. Does anyone know what is going on?

In the previous project using the same instruments with same presets loaded??

What instruments?