At random times, a nether portal will send me to the coordinates of the location I had just left rather than the original corresponding coordinates. For example, my main overworld portal is located near 1054, 69, -1572 which takes me to a base I built at around 130, 95, -180. This last time leaving from the overworld location dumped me into 1054, 69, -1572 in the nether rather than the usual location. When I arrive, there is no nether portal behind me and I have occasionally been stranded with loot I was transporting from my bases and have no corresponding obsidian/flint and steel to build a portal. This has happened with multiple nether portals across my network, and includes porting from the nether into the overworld. I don't really have any screenshots as I can't screenshot the portal I left behind since this bug happens randomly and building a portal at the new location does not take me back to the portal I have left.