Router configuration

I have a Forerunner 745 and Spotify Premium for music and podcasts. My WiFi is a solid balanced 400 Mbps. Downloading songs or podcasts can be excruciatingly slow, and occasionally fails. I have:

--

13.30 - software version

4.01 - Wi-Fi

22.07 - Sensor Hub

---

It has been this way consistently through a couple of watches and routers.

I'm wondering if there is some kind of fixed and ideal Wi-Fi router configurations that plays best with the Garmin Forerunner watches.  I'm just fishing here. 

Is it possible to change router configurations of some sort, to result in smoother and faster loading on my Forerunner?

Band? MHz? channels? SSID? Anything?   Is my query here ridiculous and shows a complete lack of understanding?

By slow...a spotify playlist of fifty songs. I selected "Update" and it's five or more minutes. A new hour podcast is two or more minutes. Obviously it's not life or death, it just seem to be a disconnect from the available Wi-Fi speed and the actual download time.