@KBancroft Hello,
Could other devices like laptops or phones get Internet from range extender?
1. If RE leds are On but none of the devices have Internet from RE, please try this troubleshoots guide, turn on RE DHCP and set up a static IP for RE:
Has connected to TP-Link extender but no internet, what can I do?
https://community.tp-link.com/en/home/forum/topic/198516
2. If other devices could get Internet, only camera says offline, you may need to contact camera support and see if they have any suggestions for troubleshoot.
Make sure camera could get Internet from router, not blocked by router advanced settings.
May I know the model and hardware version of the range extender? what is the model of your Router, thank you.