Portal linking issue

Realm created in version 1.12.0 set to 10 players max. First portal linked, created a tunnel to connect future portals. First portal became the desert portal and was then linked correctly. Second portal was linked after known as the spawn portal. Traveled a long distance to a tundra and created and linked the tundra portal. Traveled through the nether to expand the tunnel to the tundra portal; now finished. Started maintaining a village with 12 librarians. 5 player have joined the realm. Updated to 1.13.0 Pillagers invade my house. Trapped their captain in a boat. Visit nether through the spawn portal. Nothing unusual happens. I go back through and suddenly I am transported 1,000 or so blocks away from where I’m supposed to be. Where ever in the overworld I was transported I was not accompanied with a nether portal. I walked back to spawn to visit the nether again. This time I was transported 1,000 blocks away in the nether accompanied with a portal. I traveled back again and did not want to return.

I don’t know what is causing this. It could be a entity related issue.