On my realm, defeated ender dragon to get all 20 portals, labelled each with orange wool above gateway, went back to overworld and bed in the stronghold had disappeared. Went back to stronghold to place new bed and it wouldn’t let me, then mined in location and previous bed popped up, also on the other side. Went back into end portal, spawned and two of the end gateways had been replaced almost entirely with end stone, labelled again with stone while I went to get more orange wool. Came back. Broke through end stone to reveal gateways again and one had the bedrock overwritten by end stone and the other had replaced all the wool. Upon going through the broken gateway, teleported to end location as. Or Al, went back through and the end spawn platform from my original spawn in the end was replaced with end stone. Mines that out and tried gateway again but now links to under the end island. Went back into overworld and came back into end with beds replaced in stronghold and upon return, end stone that had replaced original spawn platform was missing the middle section