Whats the trick with the oil pan gasket change.

The first error you have made is thinking the oil pan was leaking. With liquid sealants, the gasket should not leak. The leak should be coming from somewhere else and it usually is from top of engine, the valve cover gasket.

Since you have done repair, improper application of sealant can result in leaking and trick is you need to apply the sealant so that it is like a thread running across the seated areas and when pushing the oil pan up, do not compress manually. After putting on all the bolts and nuts, evenly tighten the bolts and slowly bring the gap closer evenly. Ensure all surfaces are clean and dry.