This situation has consequences.

Postdoctoral fund application disciplines, a considerable number of postdocs are interdisciplinary and deviate far from the original doctoral direction. Some people do it because they don’t like the original direction, or for other reasons. The research content you apply for must be consistent with your original doctoral work.

Hook.

Postdoctoral funding projects in different disciplines may have different evaluation criteria and competition.

Generally speaking, competition in some popular subjects or research fields will be fiercer, and it may be more difficult to successfully apply.