Which driver are you using?I Confirm that the TP-Link N300 (TL-WN823N) works with Osx (thus with Sierra aswell). No dropouts, full speed, and in my opinion..the best wireless option for hackintosh. Nice for a 15 dollar wifi stick!
Yes it works under Mojave (I tried TP Link WN 823 V2 using the latest drivers for V2).
Just a side note: Before connecting the wifi stick the first time, install the drivers and reboot. If I first connect the stick and install drivers, I get a message, that no NIC is available sometimes.