I'm using the TM-AC1900 to RT-AC68U from firmware AC1900_3.0.0.4_376_1703 to 384.4_2. The download and upload stats are working perfectly fine under traffic monitor tab. It is just that the statistics tab, the download and upload are reversed or download isnt working. Reboot didn't work and it did erase all my data.Running the same firmware on my RT-AC68U rev C1, having Signature Version 2.066, I can confirm that Download stats are working properly on my device. From what firmware version did you upgrade from? If it was on 380.xx, have you initialized(factory reset) your router after firmware update? And manually configure everything? Also, make sure Signature is up to date.
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