Mine is exactly the same . If not started for a few days the oil pressure warning light takes as you say a few seconds to go out and the engine is noisy , hydraulic tap pets, etc., until oil circulates.
The longer time , days , weeks, months , between start the longer , slightly, it takes for the oil light to go out .
Similarly at oil changes it takes even longer for the light to go out as the pump must fill oil lines that were drained and oil filter, etc. Before pressure can be built up.
This is normal on any engine unless as in some vehicles the complete oil system is primed by external means.
The oil drains from the top components down and the longer a vehicle is left unstated the longer on some systems without non return valves, etc., the longer it takes to build up oil pressure.
It also depends on where in the oil system the pressure switch is. Immediately after the pump pressure outlet the quicker it will go out.
As long as it does not take longer than say 30 seconds personally I see no problem BUT one must wait till the light goes out before using the throttle.
On older vehicles the trick was to turn over the engine until the oil light went out which out using the choke or not auctioning the ignition system before allowing the engine to fire up thus preventing component wear from no oil pressure.
After the first start the oil system will be primed and subsequent starts will result in quick oil light going out.
If it is agreed you have a problem so do I but as yet I do not think I have but still do not like the noises until the light goes out.