You can duplicate gravity blocks by passing them in and out of an end portal or gateway using a sticky piston, collecting the resources on the other side. This exploit is not working.. all late game players rely on this method to get sand. Its broken. Its a bug that was supposed to be left in game because obviously sand is non renewable. The end gateway also displays no light.
Linked issues
duplicates 1
Attachments
Comments 7

Thank you for your report!
We're tracking this issue in MCPE-185542, so this ticket is being resolved and linked as a duplicate.
That ticket has already been resolved as invalid. Please take a look at the parent ticket (MCPE-185542) and see if an explanation is provided there in the description of the ticket or in the comments for why this issue is invalid.
Please do not duplicate your own reports.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support (Technical Issues) – 📧 Microsoft Support (Account Issues)
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki
@Psyionysus it's a bug/glitch that players were abusing. It's not a feature. And sand is renewable, just not reliably.