YES, someone told you right. 20w50 is not the right Engine oil grade choice for your car, at least not for the car with just the mileage of 86k kms. (However, if the mileage is accurate)
I suggest you first switch to 10w40 or 10w30 and regularly monitor the Engine oil dipstick for the Engine oil level, if the Engine oil level is getting low, then I suggest you stick with 20w50 as the thinner viscosity oil will not be suitable for your car now being used the oil grade of 20w50 for a while now by the previous owner, and if the level of Engine oil on the dipstick is okay, then after one or two Engine oil changes with 10w40 or 10w30, try 5w30 Fully synthetic and repeat that practice mentioned above, which is actually the recommended oil grade for your car.
The rest is your choice.
I hope it helps.