Hi everyone and nice to meet you all!
I have the same issue with my RT-AC87u, starting few month ago. I tried to install also a KIWI log-server to see the logs in the moment of rebooting, opened multiple ssh connection and monitor in the same time the CPU load, processes, other logs etc. but nothing seem to indicate why the crush/sudden reboot.
Then i searched many hours over the internet and, even on the official ASUS site the last firmware is 3.0.0.4.382_52545-ga0245cc , there seem to be newer versions too according to this security sites:
While studying for my master's degree in cyber security, I co-authored a paper regarding the rollout of IoT devices. Read more.
www.kroll.com
nvd.nist.gov
www.vicarius.io
An improper access control vulnerability exists in RT-AC87U all versions. An attacker may read or write files that are not intended to be accessed by connecting to a target device via tftp.
vulners.com
So, it seems that all versions bellow 3.0.0.386.xxx are afected... and we are on 3.0.0.382... The problem is that i am not able to find any 3.0.0.386 version and i wonder why...because now i am sure they exist.. Maybe even newer than 3.0.0.0386.46061..
BTW, i do not think that it has something to do with Win updates, but with browsers, mostly with chrome (at least in my case). I observed that this occurred very often when i used chrome and left a lot of tabs open over night, then the second day, as i was trying to refresh one page, all of the sudden the router was rebooting it (buffer-overflow? broadcast-storm?).
I reset the router to default, did new settings from the scratch: new users-names, new passwords, new ssid-s etc.. I even hide the ssid, and put MAC filtering..nothing helped until now. But i am very sure it is a software problem, hence the router is rebooting also at 3 A.M. when everyone was sleeping in the house... (i exclude power problems, hence the router is connected to an UPS and next to it it's a 8port switch witch does not reboot, but maybe could be the router power adapter faulty?? -Also hard to belive since so many people are complaining about the same issue in the same time..)