A roller ball catch is commonly used on interior doors such as accordion, louvered, bi folding, closets and light or medium service doors. The use of a ball bearing type keeps the latch rolling smoothly against the lip or striker plate to close it. The other door has a dummy handle that does nothing.
Step 1- Determining the Cause
The ball is spring loaded to have good tension to keep the door closed until you pull on it. From time to time the striker plate will get out of alignment with the roller ball. When this happens you need to measure the two plates and make sure that they are on the same level.
Step 2 - Making the Adjustment
Perhaps the door has dropped down some. Adjusting the screws in the hinges sometimes fixes this problem by raising the door. However, if it doesn't you will need to remove the roller ball catch and the strike plate and reattach them in a new area or adjust the attachment of one of them to where they will meet smoothly again. The roller ball catch is a single action with a spring-loaded ball bearing that is self-adjusting unless one or more of the doors gets out of alignment.