I'm having that trouble with lots but not all seat maps for 777s for flights from Feb to April. I was having all 777s but most have come back up in the past couple days. The maps for routes that have definitely been Polarized (NRT SFO) are back, as are 773-ERs that prob aren't scheduled for Polarization for a while. Maps for 789s never went away for me.
What troubles me is that on my computer my seat assignment for a mid-Feb NRT IAD flight (in Y) is gone, though it's still there on the app. It's row 20 in a seat that should be a front row wall or a new Premium Plus seat but with the craziness of some planes having a row 19 and some not, I'm afraid I'll end up trapped in a window seat. So now I guess I have to check six times a day in case a row 19 suddenly appears in front of me. Sigh.