I’ve accepted an offer for a new role and have started filling in all the forms and bits for the background checks. Apparently these can take up to 4 weeks. Once they have been completed I will be given the formal employment contract. I have a 3 month notice period at my current job and am planning to resign once I have the contract from the new place (which is what I have always done previously). However the new place seems to be assuming that I will be handing in my notice ASAP and will be starting in 3 months time (not 3 months + time taken for background checks). I get the impression they are not thrilled about the length of my notice period.
I’m obviously not going to resign before I get the contract, but am worried this is a bit of a red flag. Is this sort of request common?