From the Dragino product selector page:-
There have been several manufacturers of such faux gateways over the years and sadly it took a while for them to recognise the problems ensuing and even longer for their sales channels to catch up and update their own websites/info to highlight the fact they were LoRa only.
In the early days of TTN, when ‘proper’ GW’s cost >>$1000 these were a way of starting to use and experiment with LoRa and a subset of LoRaWAN, and were tolerated. Lots of web guides refer to them and give how toos on connecting to TTN and unfortuantely the Internet abhors censorship so its difficult to go around and weed them out. A simple search of the TTN Forum before purchase would, however, have flagged the problem and instruction to not use/connect to TTN.
A LoRaWAN gateway is capable of receiving on all 8 assigned channels/frequencies and multiple SF’s simultaneously, where these by definition can only handle 1 or 2 depending on config. That means they can give false impressions of local coverage to other users and in the case of devices using ADR totally disrupt the signal evaluation algorythms. In addition, and potentially worse still they present themselves as Gateways to the backend NS, which may, depending on signal strength, select your gw to send a downlink to a nearby node, this could be e.g a join request/acknowledge, ADR instructions as above or any of a number of MAC commands, or indeed a user payload downlink. Your ‘GW’ would be asked to send but would be physically incapble of completing the task. The user would not be serviced and the NS would have no way of nowing it hadnt worked!
Today compliant, 8 channel GW’s are really cheap - Dragino to a good one the LPS08, or some of ts larger brothers (LG308 etc.), and ofcourse there is the TTIG, plus low cost gateways from RAK, Pycom, iMST and many others ($70-$150) plus more capable units from RAK, Dragino, Multitech, Mikrotik, Teltelic, and again many others in the $150-350 range.