The reason wasn't specified. Are they supposed to specify the reason like security check?
The officer told me to send CV, job offer and support letter on email. Even though these were available at the interview so this ask looks to me more like a facade.
Sounds like the typical "administrative processing". They typically do not give any reason, just that they "need a bit more information" and "the processing typically concludes in 60 days or less". You may be lucky and that is the case, you may be unlucky and it is stuck for years. Even if you're from e.g. the developer of curl from Sweden in 2016, not a nuclear physicist Russia or Iran in 2025: https://daniel.haxx.se/blog/2020/11/09/a-us-visa-in-937-days...
I've heard about a person waiting for 4 years for their B-1/2 U.S. visa recently.
I haven't heard a single story where any kind of feedback or realistic timeline was provided to anyone, be it the applicant, the employer, a lawyer, a congressman. Not once.
The officer told me to send CV, job offer and support letter on email. Even though these were available at the interview so this ask looks to me more like a facade.