Based on some reviews, this is a sub-par router, especially in terms of reliability and 2.4GHz performance. Perhaps they're just trying to liquidate their stock of it and make a few bucks while they're at it.
Apparently, the reviews in Amazon tells AX1500 is a lemon. AX1800 probably fixes a few things but still problematic:<p><a href="https://www.amazon.com/D-Link-802-11AX-Wireless-Internet-R15" rel="nofollow">https://www.amazon.com/D-Link-802-11AX-Wireless-Internet-R15</a>...