Seems like this site is using “Shadow DOM” techniques that are causing the problems with auto-fill. The good news is that Bitwarden has developed a new version of their auto-fill code, which can handle these types of sites. The bad news is that they are still working on some bug fixes in this new code, so we will have to wait a bit before this improved functionality will be available.
For what is worth, I’m an ING user from Romania, their site being https://homebank.ro, and their integration with any password manager was always horrible. Its such a frustrating endeavor to use their site.