Steam downloads slower than expected. (5-15mbps)

[Senzelian]

I just got my Steam Deck (64GB) and have experienced slow downloads within Steam.

My internet connection:
100mbps down / 20mbps up

I have tried using the Steam Deck with Wi-Fi and a wired connection by connecting a Dell DA300 USB C dock. With both options, the download speed hovers at around 5 - 15 Mbps.

I am downloading and installing the games to a Samsung Evo Select 512GB SD card, but have also tried the build in 64GB EMMC storage.

When I do a speed test within the desktop mode, whether wired or wireless, the Steam Deck can achieve speeds of up to 85mbps. I also have no trouble achieving 95mbps on my desktop when downloading games on Steam.

Within my home network, I use a Ubiquiti Unifi 6 Lite, which is connected to a TP-Link TLSG2428P switch, which then connects to an AVM FritzBox 7590 router/modem.

I have tried to increase the download speed limit to 1000000kbps (1000mbps) and I have tried disabling the network power management within the developer options. None of which resulted in a change.

One thing that is interesting to note, is that I had also slow download speeds during the download/update of Proton within Steam and a few other Steam-related updates, for which I then connected the wired connection. At the time that helped, but as soon as it began downloading a game, it went back to the aforementioned 5 - 15Mbps.

[Senzelian]

Update:
I just had an instance now, where the Deck was downloading at full speed.
I connected the Deck with the Dell DA300 directly to my router and that worked. I then decided to connect it directly to my TP-Link switch, which also worked. I then took it to another TP-Link switch, and the speeds slowed down again. So I took it back to the router, but the speed was still slow.

It's a really strange phenomenon, that I can't quite replicate. So far Wi-Fi didn't work properly at all.

[Senzelian]

Update:
I now connected my Steam Deck to a hotspot on my phone (Google Pixel 6 Pro), which is connected to my in-home Wi-Fi. This way the Deck always is able to achieve max download speeds.

So to recap:
Connected to hotspot: Good!
Connected to Wi-Fi AP: Not Good!
Connected via cable: Sometimes good!

Not exactly a fun experience :(

[Why u mad bro?]

I have the same issue... only in way worse. I have 50Mbit Download Connection which is already slow enough for me but Steam Deck tops it off with sub 1 MB download speeds. What I found out is that if do speedtest via Chrome it has full download speed. So it seems like this is problem with the Steam application rather than the Deck itself

[Senzelian]

And another update:

I just tried connecting the Steam Deck to my Lenovo Thunderbolt 3Workstation Dock Gen 2. That worked really well, and I was able to achieve max download speeds wired.

So my conclusion so far is:
Either natively over Wi-Fi, or with some docks, the Steam Deck will have bandwith issues when downloading games on Steam. I still have no idea why.