Animation with Trigger is not working as it should

Hello there,
I’ve set up some custom animations which get triggered by clicking on a picture while the slide show is active. For example: I click on a picture which triggers an custom animation so that another picture appears. The problem is, it only appears for a quarter second or so and instantly disappears again. If I do the same on Open Office for example, it appears for ever, which is what I want.
Any idea why this happens in Libre Office Impress?