how am i not connected to my network extender?

I thought id bring out an old network extender, WN3000RPV3, now that i know quite a bit as opposed to nothing. i reset it twice for two reasons at this point; it set up rather quickly both times compared to the other two brands i have. the download speeds are not realistic at all so far. the upload speeds sometimes are. aside from that, i cannot access the extenders settings to fine tune it and make changes; it keeps telling me I'm not connected to it when i obviously am, otherwise id get absolutely nowhere. mainly what id like to do is be able to try and update it now that i see there are firmware updates available since i stopped using it some time in 2017-18. ultimately because i couldn't get a good connection out of it and i couldn't even update it because of it being a zipped file; which isn't free to unzip... anyways, i don't have a working windows computer ether; so no matter if i try .net, .com or .local i dont get any results other than I'm not connected to it or the .local link fails to eventually load.

what am i missing here? is it unsupported now some how or? obviously its connected and getting some type of connection with spectrum.