No, you can’t connect your Wyzecam to your 5G network. The Wyzecam only supports 2.4GHz radio.
And note that when you are setting up a Wyzecam, you have to ensure that your smartphone is connected to your 2.4GHz network. In some (many?) dual-band households, the 2.4G and 5G networks both have the same SSID. It’s quite possible that the smartphone will be associated with the 5GHz network. When the smartphone then attempts to ‘add’ the Wyzecam, it will do so using the details about the 5GHz network, not the 2.4GHz network. The workaround for such a scenario is to temporarily disable the 5G network on your router, thus forcing the smartphone to associate with the 2.4G network.
It may be that your Wyzecam is just too far away from your router to get an acceptable 2.4GHz signal from it (or vice versa - WiFi transmission is a two-way street). Sometimes you can improve things by changing the channel used by the 2.4GHz radio in the router.