@terziyski as per the post you linked me, thats exactly the issue here. from the post: "But I cannot access the device via the IP address of the connection" - this says it all.

also I strongly disagree with the accepted solution of that linked post. it is totally unacceptable to "fix the issue" by resetting the device.

yes, I can't access the satellite router USB anyhow and yes, its USB port is not working at all under satellite mode.

this is basically similar issue we had back in a day with the firmware update of the satellite router - the only way to do that, was to hard-reset the satellite router, update the firmware and re-enable satellite mode again. fortunately, this issue was patched by one of the firmware update, and now in the main router, we have a dedicated window with listed satellite router and ability to check for firmware update as well as to directly update the firmware of satellite router from within the main router.

asking for a same treatment for the USB port. clearly if one is possible, the other is also possible by design (especially when other brands like ASUS are able to)