I'm glad I got YB stations with my COMET OutB250 vertical antenna.
I think they should have used the recommended frequencies for the FT8 contest
FT8 DX Contest 2020 Suggested frequencies are: 3.590-3.600, 7.080-7.100, 14.130-14.150, 21.130-21.150 and 28.160-28.200 MHz. Set the WSJT-X dial frequency to a multiple of 2 kHz, for example, 14.132 MHz. (Note from Japan: For JA-JA and JA-DX contacts, use 3.522, 7.032, 14.078, 21.078 and 28.078MHz.