Devices suddenly dropping in LQI

I've had HE setup with a bunch of repeaters around the house with no issue for over a month now. All my repeaters have had 250+ LQI. Strangely today a full floor of devices stopped working. When checking the getChildAndRouteInfo page, it seems the repeater dropped drastically in LQI down to 24. I checked all other repeaters and devices everything is connected and working. Does anyone know what could have caused this and a recommended fix?

What repeaters are these? I have had this happen with the Tradfri USB repeater when I had something plugged into the repeater's USB port. My solution was to never use the USB port.

Hi @aaiyar
Yes, they're the IKEA USB repeaters.
What did you plug them into? Just any other USB power port?

Actually since you pointed that out, this is the only repeater plugged into an iPhone plug USB & not the USB port it came with