WD My Book 4 TB drive connection on Nighthawk D7000 Readyshare

Hi all.

I currently have a 2 TB seagate shared drive attached to Netgear D7000 router working fine. Need to use a 4 TB for lots of storage and tried the WD MyBook 4 Tb mod WDBBGB0040HBK. Removed the original WD Discovery software and reformated T4 with NTFS (as well as Xfat). As noted on the attached image, only 200mb is available. I have perused the online netgear list of compatible external drives while not conclusive as not an up to date list it does make you think it would work.
Any suggestions please.  Thanking you in anticipation.