Got background Checked in Vancouver when apply for H1B re-entry

I was wondering whether anyone knows how long it is usually take now.

I went to Vancouver for a H1B re-entry visa on June 4th, but was told to be delayed due to background check, It has been almost one month now. My major is in chemistry, and I did some sensitive research project before. I am currently work remotely for my company in USA.

I was wondering if any of you guys have this problem before, and usually how long it takes. What can I do now except waiting? It is a terrible feeling.

Good thing is that I have Canada PR, so I can stay here as long as I want.

Thanks for any tips, suggestions, or experience sharing stories.