Random audio stimuli doesn't play through with other type of stimulus on screen

OS: MacOS Catalina
PsychoPy version: 2020.1.2
Standard Standalone? (y/n): Yes

What are you trying to achieve?:
I am creating an auditory oddball task where participants here two different sounds (.wav files) they have to move their position on a slider to indicate what they think the proportion of sounds are (which is being presented more),

I have the two sound files saved separately and have created an excel spread sheet with the correct proportion that I want them presented in. I have looped that trial for it to be random and the sounds play randomly. However, when I add anything else to that trial in the builder, only the first sound plays and not the rest.

This has happened twice - once when I tried adding a slider response and again when I tried displaying an image on the screen simultaneously. Does anyone know why this could be the case?