It could be the realtor did not present your offer, maybe because the seller’s realtor wanted his own buyer to make the purchase (so he could collect on both sides of the transaction).

This happened to my dad once. He made an offer, no response came back. Weeks later, he noticed the price was reduced to just above what he had offered. My dad called the seller directly at that point to see if he would take his offer now. The seller said “what offer?”. His realtor had never presented it to him.

This could be the case here too. Or maybe the buyer selected brought all cash and offered a quick close – could be the buyer had to have the $$ very very quickly.