Listing agent not responding to my Realitor

[Jeffrey McKee]

My Realitor has been trying to set up a showing for a duplex in Dallas but the listing agent will not respond and just recently they cancelled showings. I suggested we reach out to seller directly although my Realitor responded it is considered unethical. Is it unethical for me to contact seller or just the Realitor? I am pretty sure it has not gone under contract and it is still active on mls. Any advice?