Cannot vote people outside top 100 witness candidates

Hi everyone, when I am trying to vote for someone who is not ranked as a top 100 witness candidate, I am using the username to vote, but it seems that the voting is in progress but never finish ( a small circling tag indicates the voting is still in progress, even after a couple of hours!).

When I vote for the witness candidates who appear in the witness top-100 ranking, the voting is cast very quickly.

Anyone can help me with this?

Thanks a lot!