Have the engine at idle and very thoroughly warmed up. Loosen the oil filler cap and determine whether it more or less rests in place (neutral or a little negative pressure) or if it wants to lift up or dance around much (positive pressure). If the pressure is positive your rebreathing system is not working and you need to go through it to find where the clog is, e.g. the flame trap/orifice, oil separator, etc. One way or another the crankcase gases should get routed from a passageway thru the cylinder head back to the main air intake, between the air cleaner and the throttle body. So you should find a hose is present for this purpose. The flame trap if present is at the air cleaner end of the hose.

There may be some seepage of oil due to a rotten gasket around the filler neck, or at other places on the engine via various oil seals being not in good condition. If the crankcase is not under pressure these are things to watch. If there is pressure, it will be relieved one way or another, possibly by blowing out of a seal.

Occasionally an engine in very poor condition will have so much blow-by gas that a properly working rebreathing setup won't handle it. This seems unlikely on a car as new as yours.