I can confirm this issue.
Running Minecraft 1.13.0 Bedrock Dedicated Server, with the following clients intended to start a team fight:
Windows 10 edition (Intel, 2 clients)
Samsung Galaxy Note 10+
Samsung Galaxy S8+
iPhone 6s (iOS 13.2)
iPhone 6s Plus (iOS 12.4)
OnePlus 3
iPhone Xr (iOS 13.0)
iPhone Xr (iOS 13.1)
Of the 8 clients connected, both iPhones Xr were kicked from the server without being able to go through the portal. The two Samsung devices and one Windows 10 device was able to teleport to the end platform fine, but the rest of the clients suffocated in walls and got stuck on the loading screen, having to reconnect.
Portal is sending me to the same coordinates in the Overworld. i.e. 1500, -500 in the overworld should've sent me to 187, -62, but it sends me to 1500, -500 in the Nether
I've replicated this using Bedrock Dedicated Server 1.13.0 with Android, iOS, and Windows Bedrock clients on both tablets and cellphones across multiple computers and devices. I've noticed that the behavior for this is not consistent, and sometimes it sends me to the right location in the Nether, but whenever it does this no one is able to go through another portal, and people have to log off and log in again.
I just want to note that the consistency of this issue is extremely inconsistent. While preparing for a team fight of the ender dragon on Bedrock Dedicated Server, we had a base at ~(1500, -500) and a stronghold at ~(1500, 2700). Nether portals were supposed to connect these together, but everyone going through the portal for the stronghold from the Nether landed at the (0, 0) portal.
We had 8 clients connected, and 2/8 were teleported to (0, 0), while another 3 were unable to connect at all after going through the portal and had to restart the game.