@cashchow In TP-Link's terminology that's called WDS/RE mode. Unfortunatelly C3150 doesn't support this feature - here's the list of router supporting this feature. And here's how to configure if...

@btan Use this story for configuring your devices to avoid any IP address conflicts.

@PearlyH-24 Check your RE configuration - use this story as an example how to configure your devices.

@Denis28 Go through this thread for your issue and try its suggestions.

@Lumpy102 Use this guide for configuring the RE in AP mode.

@sabinoFilhoMark Try setting the RE540 with a static LAN IP address 192.168.0.254. Reboot the Archer C2300 and then test if the issue persists. You can always contact your local support if nothing...