Duplicating and randomly generating Nether portals/Infinite obsidian glitch

When going though a nether portal (portals A) in the nether, I end up going through a portal (portal B) that I didn’t build and is about a chunk away from the portal I had originally built (portals A). I then break portal B and go back though portal A. When I leave through the same portal, it spawns another portal (C) right beside portal B. I repeat this a couple of times and I end up with about 4 broken portals that I never built. Sorry if this is confusing, it’s just a big problem since I always end up at the random portal and never the one I originally built. This can also be seen as an infinite obsidian glitch, so there’s that.