Disclosure: I am a home network novice, I know enough to be dangerous. Pardons for lack of information or clarity.

I am in need of getting a workshop that is disconnected from the main building (about 200 feet) connected to the internet. The main network is running off of a Netgear X6S AC 4000 R8000P that has a TP-LINK CPE510 acting as a transmitter and an additional TP-LINK CPE 510 set as an Access Point. I am attempting to connect a Netgear AC1750 R6400 v2 to the LAN coming off of the Access Point. 

When I connect my laptop to the Access Point LAN, I have a perfect signal, no degradation and speed test shows little loss in internet speeds. When I connect the R6400 v2 to the Access Point LAN, the router says it has no Internet Access. When I test the same router with a direct connection to the base internet, it runs. I am sure I am missing something (probably obvious) but could really use some guidance. Or resources to turn to, i have gone through a few posts on here already but nothing I have tried has worked thus far.