F5 Sr. Software Engineer interview questions

Twice it had happened. F5 hr (first time) or third party consultants (second time) first take ctc and expected ctc over phone, then start scheduling interviews. After successfully clearing 3-4 rounds of discussions, HR will call and ask for expected ctc and try to offer less than our current ctc (not sure how they expect anyone can accept ctc less than their current ctc) and they say it is crossing our range for the role. Firstly they know their range for role and our ctc and expected ctc then why do they waste others time and energy. Second time I clearly told recruiter that schedule the discussions only if they are fine with expected ctc. Recruit can reply to this review and can tell that my expectation is too high and unrealistic. For those people I had expected 8-10% over my current ctc.