What happens in dukkham ara ?

In Jain cosmology, Dukhamā Arā is the fifth ara of Avasarpinī (the descending half of the time cycle). It is a period of more sorrow than happiness, with weakening of human strength, lifespan, morality, and spiritual discipline. In this ara, true religious practice becomes very difficult, and liberation in the same life is generally not attained. ( jainknowledge.com)

So, in simple words: in Dukhamā Arā, suffering increases and spiritual conditions decline. ( jainknowledge.com)