Confused about the assembly results with Hi-C data.

[YuChrming]

Dear writer, I was very confused about the assembly results with Hi-C data. I used hifiasm to assemble a triploid genome, and the result looks perfect with N50 > 15M and contig-quantity about 760. Some contigs even approach to chromosome. But when I use them to scaffold by juicer, the Hi-C heatmap is extremely sparse. Even 2/3 of the length of a 35M contig has none Hi-C signal. What caused this?

One more question, a region of a haplotype always missing no matter how I modify the parameters, how to supplement?

Appreciate and look forward to your reply!