Seconded - those RealTek dongles are no good. For my Macs, the IOCrest USB4 adapters with the AQC113 chipset have been rock-solid and can saturate my 10Gbe net

Seconded - those RealTek dongles are no good. For my Macs, the IOCrest USB4 adapters with the AQC113 chipset have been rock-solid and can saturate my 10Gbe network. They do run hot but no stability issues. That's what I use and recommend. The newer RTL8159 based dongles are smaller, cheaper, cooler, and can do 10 Gbe on paper. But they top out at 7 Gbps on Macs, which don't implement the USBx2 spec.