well i personally can't close it but it's a duplicate of MCPE-34662
Have the same problem on 1.5.1 with networks ranging from nat type A to nat type D. On all the networks I've tested (like 5 or 6) i have the same problem.
I actually have just created an issue whch I'm going to close as duplicate since I had no success finding the correct one.
What I hate most of all here is how support hasn't answered me within... a week
Now I can at least see something's being done...
Also using the phone login, will try email logging in right now.
Yes this is it. With email xbox login everything works fine on my side.