Similar situation here.
933 nights, 13 years as Plat.
Hit 50 nights for 2018 on Dec 31, so logged in to see if my SNA's had appeared (nadda yet). Went to check if I was finally being correctly shown at LTPP (as oppposed to LTP) - but nope. On the Overview tab, I am now just "Platinum Elite" (still no Premier recognition). However, a few lines of text below that, it does say "You are Lifetime Platinum Elite".
So someone what of a tiny conflict that I can live with - but just keen to get my Premier recognition now, having waited most of last year for it (for no good reason).