Issue was Solved by re-formatting the Mac partition of the external drive. Apparently it was broken.
After that - the issue does not exist anymore.
Cheers to all!
Same thing happens with latest firmware from the ASUS site - 3.0.0.4.378_6975 although it says it updated an issue with connecting to USB hubs.
This is the log from it:
Jul 7 21:09:14 kernel: usb 1-1: new SuperSpeed USB device using xhci_hcd and address 2
Jul 7 21:09:15 kernel: xhci_hcd...
Hi All,
I have the following problem on latest Asus auto-updated firmware (30043784585) and on latest Merlin's (378.54_2)
When I plug in my WD MyPassport 2TB external HDD the router goes into a reboot loop.
If I unplug the disk - it works fine again.
HDD is formatted in 2 partitions - 1TB Mac...