@GPBH It depends how old is your device - if it's under warranty contact your retailer, otherwise contact your local support for assistance.

@Rajasekar If you use a DSL modem, probably this video guide could help you to resolve your issue.

@SharkAttackRJ If you have an ISP modem router before AX90, you probably are behind a double NAT. If you want to avoid that you may refer to this guide (in case ISP modem router allows bridge mode)....

@SharkAttackRJ Both routers are compatible, so don't worry about that. Just follow the guide I posted and you'll have a mesh network between them.

@SharkAttackRJ If you set AX53 in access point mode it won't be in a mesh with AX90. You have to add AX53 as a satellite device to build a mesh between these - here's a guide for that (use the WPS...

@SharkAttackRJ AX90 supports Onemsh, while AX53 supports zeasymesh. If you plan them to be in a mesh you should use the AX90 as a main router and AX53 as a satellite device.