Debugging step buttons disabled in Eclipse Oxygen

I have upgraded Eclipse to Oxygen, with Scala and Python added. I noticed that when programming in Java, the step commands of the debugger remain disabled. I can run the debugger, and it will run until it hits a breakpoint, but then i cannot step in or over. I can only stop the (local) VM.

Any thoughts?

How do I enable debug toolbar in Eclipse?

2.1. First, we need to start the Java program within Eclipse in debug mode. This can be achieved in two ways: Right-click on the editor and select Debug As -> Java Application (shown in below screenshot) Debug the program from the toolbar (highlighted in below screenshot)

In my case increasing the "debug timeout" value resolved the problem. Thanks to @Shahbaz Ahmad comment.

Preferences >> Debug >> Connection Timeout