Apologies if this is in the wrong place, I just joined the forums and really just joined the hobby in general. I recently bought a few slabs, two of which were graded in 2021 according to the CGC verification and have the "CGC" watermark very faintly behind the grade. However, another book I bought does not. The book shows up on the verification page, it was bought from a reputable ebay seller, and was graded in mid 2020, but the white label is just white with the grade, no watermark. I couldn't find much about it online but it seems like this watermark was started some years ago and best I can tell should be there. Should I be concerned or is that watermark not necessarily ubiquitous? Thanks in advance for any help!