Why is the service from Guangzhou South to Rongchang North suspended?

Weather reasons.

Recently, some sections of the road have been affected by heavy rains.

Due to heavy rainfall in the area north of Zhengzhou, which blocked railway transportation, some trains originating from and stopping at Guangzhou South Station were suspended. Passengers who have purchased tickets for the suspended trains can go to any train station window across the country for a full refund with the original valid ID used when purchasing the tickets no later than 30 days from the date of boarding (including the same day).