Watch the video to see this bug. This bug I see on other Realms, not only my.
https://drive.google.com/file/d/1Lukno44D-fTdM_u6I1MXlGSiokQMlhhZ/
(I uploaded it to google drive because it over 10MB.)
REALMS-3778
Nether Portal Bug
Resolved
Invalid
0
Based on the coordinates shown this is working correctly.
The coordinates of the portal in the nether are 47 58 62
The calculated overworld coordinates for that are 376 58 496
This is more than 128 blocks away from your original overworld portal, which was at 984 31 970, so a new portal is created.