please update kernel through SSH/terminal
root@DietPi:~#wget https://raw.githubusercontent.com/sparky-sbc/sparky-test/master/dragon_fly_check/uImage -O /boot/uImage
root@DietPi:~#sync
root@DietPi:~#reboot
and change CPU Governer to performance on Dietpi web GU system settings , reboot and check.
WIFI + USBridgeworks better on CPU Governor on performance mode.