Coolant keeps coming out

I drive a 2015 Chevy Trax and the coolant reservoir was always dry so I thought it was a crack in the bottom, so I got it changed. The new reservoir also dumped the coolant so I took it back to the dealers (turns out the dripping I saw was the safety thing). The dealer thought that it may be an air block when they changed the reservoir so he added coolant and let it run and watched until it started to cycle through. I went home and a few hours later, the coolant was on my driveway again. What could be causing this? Would the thermostat be causing this issue?