After receiving the registration code it seemed registration was stuck, but it worked when I switched from wifi to mobile data and then re-entered the code.

However, strangely there is a new delay problem, it was gone completely for me on the previous version.
This time msgs on wifi get transferred instantly, but on mobile data there's a big delay.

Correction: After some delayed messages it starts working again in real-time. (After switching to wifi everything still fine, every time I switch to mobile it starts with the delay and after some time acts normal again.)