The last member of the House to win the presidency was James Garfield, a long, long time ago, and, iirc, he won because of his Civil War veteran status.
I’m sure there are reasons why House members do poorly, but I’d suspect it has to do with the relatively small size of House districts and the inability of House members to gather a significant human or financial base. I’d also guess that they will be viewed as having relatively little broad experience and near zero executive experience.
Those might be unfair evaluations, but that wouldn’t stop an opponent from using such an argument.
I like her as a congresscritter, but she's our weakest candidate for president.