Using the Upgrade Planner to upgrade, downgrade, or replace objects clears the "Last user" flag. I've been able to do this reliably with objects replaced by the base-Roboport bots as well as bots from the Personal Roboport. I tested Belts, Assemblers, and Inserters. How To Reproduce: Place...

I have been able to reproduce this in 0.17.7. It is not due to a Belt->Belt setting in the Upgrade Planner. When selecting the second set of the pair, Belts can become Undergrounds: https://i.imgur.com/mm7J9VJ.png and Undergrounds can become Belts: https://i.imgur.com/7rq3iu8.png using the Upgrade P...