The latest firmware I tried is 4.6.8 and it does not have a switch between USB 2.0 and USB 3.0 Either way that does not seem to be a solution since I use older firmware (which is quite stable) with cellular modems in usb enclosures and have no idea how all this will affect their usability - dont have time to test all this just to learn if there is a "workaround".
I still would like to hear a meaningful answer (preferably from an engineer and not from a saleman) regarding a possible difference between the older and newer AXT1800, i.e. what has changed in production (a PCB layout, different component locations, different kind of used electronic components etc - there is a reason why one device is the subject to the interference and another is not ) just to make sure how to proceed - to ask for replacement or just return it and forget about AXT1800 in general (so far it was my favorite device (and I have all your routers except for cellular) due to 4 core CPU).
Bruce, could you please also have a look (or pass this info to the right person) at my investigation regarding nonstandard behavior of ipset in AXT1800 v.4.0 -4.6 firmware -I think I spent enough time and deserve the answer:
ipset & banip AXT1800