public void checkHandle() {
		if (!isValid) {
			return;
		}

		RepositoryChangeEvent openFileCountEvent =
			new RepositoryChangeEvent(RepositoryChangeEvent.REP_OPEN_HANDLE_COUNT, null, null, null,
				Integer.toString(RemoteBufferFileImpl.getOpenFileCount(this)));

		synchronized (eventQueue) {
			if (clientActive) {
				clientActive = false;
				if (eventQueue.isEmpty()) {

					//eventQueue.add(0, NULL_EVENT);

					// Send open-file count periodically instead of null event
					eventQueue.add(openFileCountEvent);

					eventQueue.notifyAll();
				}
				return;
			}
		}
		RepositoryManager.log(repository.getName(), null, "not listening!", currentUser);
		dispose();
	}
Verify that the client is active and continuing to read events
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/remote/RepositoryHandleImpl.java