Hi Sheikh,
I don’t know exactly as how they work on security thing. However I also think that it depends on how much u have traveled.
Well, in my case I’m the principal applicant and I’m from Bhutan. I had traveled to only India, Nepal and Thailand though multiple times. I thought that my security check got delayed due to this very reason. Some applicants who got DM n PPR immediately after pre arrival letter haven’t traveled anywhere at all.
I guess u have traveled to different countries as well
Why don’t you contact MP and find out the reason? They do provide u with details on why your file is taking so long after pre arrival.
Wish u good luck!