2x2 tiles (3068), types and fake or not?

[cozzie4d]

Hi all,

After buying a batch of new 2x2 tiles in light grey, I noticed that the bottom is different then most of my 2x2 smooth tiles.
I dug up a bunch of them in different colors, to compare their backsides.

My question is, do you think the grey ones (far right) are real or fake legos?

Rebrickable and some other sites showed different variants that came out through the years. Maybe my light grey ones are one of the variants.

Any input is appreciated.

[MAB]

They look real to me.

[cozzie4d]

Thanks, always good to have a 2nd pair of eyes