Using mirocast for big screen

hi there,
i had the demo running on my 3 year old huawei nova (1) it worked fine on my smartphone, but
i wanted 2 mirrow it to a bigger screen (monitor). so i bought a wifi display dongle:

Yehua WiFi Display Dongle HDMI 4K Wireless 5G/2.4G Display Adapter Unterstützung Miracast Airplay DLNA für Android/IOS/MacBook/PC auf TV Monitor/Projektor

the problem is: zwift is “jerking” (slowwww.) .on the monitor, is this because of internet connection, 7mb/s or because of smartphone? i dont have the technical background about that mirocast stuff…thank you i wonder if a samsung 10e would solve the problem

thank you