Hi @daniyalSelani,
By default prodigy sends examples to the browser and then forgets about them. This means if you sit and refresh the page over and over you'll get a new set of examples each time until you exhaust the dataset. With really large datasets where you don't annotate every example this is usually not a problem, or desirable.
A while ago we added a stream that repeats the same questions until they're answered, and you can enable that by setting force_stream_order to True in your prodigy.json file. When you do that, closing the tab will not cause new examples to be shown. When using this mode, it's possible that the same example will be shown to two users (if they are annotating at the same time.) but any duplicate answers will be filtered out on the server when they're received.
If the repeating feed is not to your liking, you can leave the option turned off and rest assured that your examples are not forgotten about when they're skipped after closing a tab. Because the server never receives answers for them, they will be shown to you again after you stop and start the prodigy server.
Let me know if this does't resolve your issue.
-Justin