Solved

Never ending builing Headquarter

First I thought, I am stupid, but now I saw 2hours before

1d 1h ... to finish

now, after 2hours:

1d 23h ... 8-(

For some accounts there is a visual bug in the countdown. Instead of switching from X days 0 hours 0 minutes to X-1 days 23 hours 59 minutes it just goes to X days 23 hours 59 minutes until somewhere around X days 20 hours the counter finally lowers the day count by one to the correct amount.

Nothing to worry about it's only visual. The upgrade finishes in time for the original schedule.