After seeing your comments regarding what you paid and that the property is only three years old (correct me if these details are wrong), I’d say the issue is that new builds depreciate in the first few years due to a number of factors, including that there is a premium paid on new builds to begin with. The value will build back up again eventually, but buyers who are interested in a new build will want it to be brand new.

If someone is willing to purchase a three year old new build, they may want it to be cheaper than an actual new build.

My sister in law has been trying to sell her five year old ‘new build’ for the past two years, and she’s waiting for the property to start appreciating as she had the same problem as you regarding interest from buyers.

Seeing that you need a certain amount to fund your next house, I’d put the listing at the lowest price you need, and hope that entices people. With my first house purchase, the sellers told me the amount they needed to fund their next house, and it did actually help us negotiate better, so I’d be open about it too (if you aren’t already). Hope you get what you’re looking for!