OK, Thanks.
I guess it is a new change since in game manual, it says " No new registrations are allowed in the second phase of the election".
"National team elections have two distinct phases. In the first phase, which lasts for four days, interested candidates can register for consideration for the managerial position. During this time, these candidates will start to receive votes from the country's users. After the fourth day, the election pool is reduced to the top five candidates, plus ties, plus those with at least 5% of the total number of votes. No new registrations are allowed in the second phase of the election. The election ends after three more days, with the candidate with the highest number of votes winning the managership. In the case of a tie, the candidate who has been playing BuzzerBeater for longer is declared to be the winner"