3rd party negotiations - please advise

Recently, two of my listed domain names got offers for $3k+ respectively. i wasn't notified of these inquiries by the platform, and only noticed it by monitoring my personal stats. being that they are listed on a brandable website, i had no way of directly interacting with the buyers. had it been my own landing page, i could have attempted to immediately engage in these possibly impulse buys and accepted the offer while iron was hot. i reached out to the support team and didn't get a response for a number of days (to judge favorably, maybe they were indeed negotiating behind the scenes) until they notified me that they will resend the buyer a link to accept, but for now it's been quiet..

Tbo, without the platform i most probably would never have gotten these offers altogether, to even get to a negotiating stage. the dilemma is how to break the barrel and still hold the wine. i'm intentionally omitting the platform's name as the purpose here isn't to bash them, rather i'm looking for anyone with similar experiences that learned how to maneuver around such situations, bringing a satisfactory conclusion for all.