Why IFormFile is null on AspNetZero ?
I tested it and not found the problem your memtioned. (net core 3.x + mvc)
What is your product version? 9.0.1
What is your product type (Angular or MVC)? MVC
What is product framework type (.net framework or .net core)? Core
What is ABP Framework version? 5.10.1
Can you share the example ? *.cshtml and *.cs
The create method in mvc controller instead of razor page.
If you are using razor page you can check this article.