yelloish apple paste like thing in under oil cap
It is possible it is oil that has previously been whipped up and has oxygen bubbles suspended in it. Oxygen in the oil would cause it to foam up. it would rise until it reached the oil filler cap. and then once the foam went down it would leave this oil behind.
After a good drive check the dipstick for bubbles, and check the cap for some new foamy oil. If it is in the cap it is possible the valve cover gaskets are leaky. There may be a drop in oil pressure who knows. I say clean it out and see if it comes back.






