I have found a bug which occurs in latest version and also in nightly versions of XCP-ng Center. We you have server list with few connection it takes about 20-25 after inputing master password when they will appear.

Missing connections list after inputing master password:

Connection list appears after 20-25 seconds of waiting:

Thank you @michael-manley

I have waiting for update for XCP-ng Center for so many years. Now adding new disks to VM when you have a lot of LUN connected to pool works very fast ans smooth.