Need to know why my clearance is being extended

I currently have a Top Secret clearance with a Counterintelligence polygraph, was issued confidential clearance through military and am getting a new job where they are upgrading me to an SSBI. I was questioned by OPM in regards to giving them my cooperation in telling my parents about everything about my boyfriend and I. I told them that my parents and I are not close, they are aware of him but do not know full details, seen pictures of us, seen us out together, and everything. I told them that I am uncomfortable with them speaking to my parents right now they are having marriage issues. They told me this puts me at risk for blackmail. A week later the job who hired me stated they are withdrawing my offer because OPM wants to extend my investigation. Every since this had happened my boyfriend and I have been very distant in which we agreed on separating and moving away from one another.

My questions are:
What further extension would OPM be investigating after I told them I am not comfortable with them speaking to my parents? Wouldn’t they just deny me and leave it at that?

I am moving back to my parents…If I reapply and OPM starts my investigation will they need to still speak to my parents?

Will this issue appear every time I apply for a new clearance or only with the SSBI?

The purpose of the investigation is to identify and mitigate (if possible) security risks. If your relationship with your boyfriend puts you at risk (which it sounds like it does) then further investigation may be needed.

It does not put me at risk.
As stated above, my parents are going through marriage issues. My boyfriend and I are not working out so I am moving back to their house in 2 months, it is so much going on I do not want to be an extra burden especially in my parents situation since they are going back and fourth with one another putting me and my siblings between their issues. Considering I’m moving back and breaking up with my boyfriend I just wanted to skip the extra issues.

I was just wondering if I told them that I do not feel comfortable with them speaking to my parents who or what would they would continue to investigate…