While some non-core router features that I do not use may indeed have some bugs, which is very common with new multi-feature electronics products released these days, I can confirm that all the core features of this router work perfectly and reliably on all three versions of firmware I have tested.
I only use QoS, port forwarding with HW acceleration enabled, firewall, and 2.4 and 5 Ghz wireless. All of that performs better than my old RT-N66U router with regards to throughput and range. Reliability is the same, no issues whatsoever across my 20 or so home devices.
Try resetting and unplugging your router for 30 seconds. Try disabling non-core router features and see if you still encounter problems. If yes, probably a good idea to delete the wifi profiles on your connecting clients and try again. Also make sure Windows devices are using the latest drivers.
I have seen Internet speculation of defects with newly released electronics that I have purchased for many years. In all cases the speculation of defects, recalls, and stop shipments turned out to be incorrect.