This are known issues about ODROID-XU4

When you remove the DC plug (HDMI still connected), the red LED stays ON if the HDMI monitor/TV generates some amount of reverse current.
It may need 5 to 15 seconds to discharge the current.
Before fully discharging, the DC-jack connection may not start the board automatically.
You will need to remove the HDMI cable or give some extra time to fully discharge.

There is no way to control the USB host power (VBUS) with software due to a missing control register.

1. If your MicroSD-card does not satisfy the following conditions, replace the card.

• The dimensions of the card must be standard.
• Check for any deviations due to wear.
• The wear of the pads will cause extremely negative side effects.

2. Excessive external force to the connector may cause damage. Please to not insert or operate as shown in the examples below:

• Do not slope the sides of the card at insertion/extraction.
• Do not twist vertically or horizontally in the inserted state.

3. To make a minimal volume of the connector, the card detection parts are partially exposed. Take care not to use excessive force to avoid breakage.

So you always meet this error message in the Kernel boot process because XU4 and XU3-Lite has no INA231 sensor on the board.

[   11.229087] [c4] INA231 2-0040: I2C write error: (-6) reg: 0x0
[   11.233666] [c4] INA231 2-0040: ============= Probe INA231 Fail! : sensor_arm (0xFFFFFFFA) =============
[   11.244188] [c4] INA231 2-0041: I2C write error: (-6) reg: 0x0
[   11.249087] [c4] INA231 2-0041: ============= Probe INA231 Fail! : sensor_mem (0xFFFFFFFA) =============
[   11.259855] [c5] INA231 2-0044: I2C write error: (-6) reg: 0x0
[   11.264473] [c5] INA231 2-0044: ============= Probe INA231 Fail! : sensor_g3d (0xFFFFFFFA) =============
[   11.274430] [c5] INA231 2-0045: I2C write error: (-6) reg: 0x0
[   11.279926] [c5] INA231 2-0045: ============= Probe INA231 Fail! : sensor_kfc (0xFFFFFFFA) =============

If you don't like that annoying message, add the driver module in the black list.

target

 sudo nano /etc/modprobe.d/blacklist-odroid.conf 

Just add this line in the odroid blacklist file.

 blacklist ina231_sensor 

The annoying message will disappear.

If you want a traditional name of the Ethernet port eth0, follow this instruction. (Written by TeHashX forum member)
You can also fix the reconnection issue on router/switch rebooting.
Instruction

Update : Latest “sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade” fixed the issue.