@Harsh_Shah It seems that R470T+ V4 can upgrade to V5 through upgrading the V5 firmware. You can try to upgrade. https://static.tp-link.com/TL-R470T%2B_V5_160809.zip

@DarylVelez Maybe your device is not compatible with English firmware. Could you show the screenshot about the issue?

@phil_rv For loop prevention, it will send a packets periodically to detect the loop. If it find the loop disappeared, the blocking port will recover. I think your problem may not related to loop...

@_dim Please note that R480T+ uses VLAN to isolate WAN and LAN. So the WAN port and LAN port cannot belong to the same VLAN. So in your topology, you cannot make port1 and port5 of R480T+ belong to...

@Barto I saw that TL-SG1016PE V2 supports PoE Auto Recovery function. This should be able to meet your requirements. But TL-SG108PE v2 should be the old version and doesn't support this function. You...

@JasonWij When you do the test, maybe need to make sure other devices will not take up your upload speed. And you also can use Iperf to confirm the maxium upload speed of the router....