I have the current setup:

1) RouterA (not TP-Link) as main router providing IPv4 DHCP and default gateway to all LAN clients. IPv6 disabled

2) RouterB (TP-Link MR600) as secondary router. DHCP disabled and only certain clients have static gateway assigned to this router

The issue is that, although IPv4 DHCP is disabled on the MR600, the MR600 appears to have caused the LAN clients to get an IPv6 address from the MR600 (they still get their IPv4 address from RouterA) which then allows the LAN clients to bypass the main router for all IPv6 comms.

Is there anyway to disable the MR600 giving out IPv6 addresses to LAN clients?

Thanks!