Always the same nonce from Android app

UPDATE: I did some test with very strange results.

I testes two case:
– try to register new user already registered;
– try to register new user;

In the first case, I have generical
Invalid access, unverifiable 'nonce' value. Use the 'get_nonce' Core API method.

In the second case, after about 30 seconds, the registration has success … unbelivable.

In both case, in log into android studio I see the same nonce (the same I posted top, always the same) :
{“status”:”ok”,”controller”:”user”,”method”:”register”,”nonce”:”4f5b39cd0f”}
but if I register a new user, I have the error
Invalid access, unverifiable 'nonce' value. Use the 'get_nonce' Core API method.
instead if I register new user:
I wait a lot and then user is registered correctly.

Hi,
I used DHC REST Client
with
www.dayroma.it/api/user/register/?user_pass=anna&email=anna%40inbox.com&display_name=Anna&username=Anna&notify=both&nonce=93c08de835…

AFTER 1:30 minutes, user is registered 🙁
Some weaks ago it worked good, Is it changed something on plugin?
There’s something wrong in my server settings?

Instead, on my android application I have a different problem: when I do an async task htto request with
https://www.dayroma.it/api/get_nonce/?controller=user&method=register
I retrieve always the same nonce…
If user is already registered, I retrieve
‘Invalid access, unverifiable ‘nonce’ value. Use the ‘get_nonce’ Core API method.’
If user is new, is registered correctly, but after one minute and half…