The Fios G1100 does not support attached USB drives. From the handbook and also from recent forum post: https://forums.verizon.com/t5/Fios-Internet/Using-an-external-USB-hard-drive-on-my-network-Fios-G1100-Router/td-p/883243.
USB - provides up to 500 mA at 5 VDC for attached devices.
For example, you could charge a cell phone. In the future, with a
firmware upgrade, the USB host functionality may be available for
other devices, such as external storage and cameras. Firmware
updates are performed automatically by Verizon.
I suggest you create a new post in the #support thread. Follow these instructions: