Just downloaded D2R on ps4, linked my account and created a ladder necro. After doing some countess runs i grabbed a 2 soc chest from Charsi stuck in Tal Eth and did not get stealth.
Because you used a magic chest. You need a white(grey) item with 2 Sockets.
Was a plain white chest, only magic properties on it are what the two runes give.
Post a picture. Load it to a picture host and post here the link.
Won’t let me post links but here is what I can post.
Imgur /a/vtHQjHw
That’s magic armor. The “Mechanic’s” prefix gave it two sockets. No matter how many sockets it has, you can’t make runewords in a magic, rare, set, or unique item.
With the </> Symbol you can post links. It will look like https://imgur.io/a/vtHQjHw
To your armor it’s a blue one this means it’s magic. You can also see it on the name of the items. Only the item name = White or Grey (normal) Spezial name like Mechanic or jewelier = Blue item (magic)