I took a look in your account and checked out your Slingbox. It looks like the router at the Slingbox's location is not allowing your Slingbox to stream in TCP (Transmission Control Protocol). What that means is the router at home is not allowing the Slingbox to stream out over the internet using the best form of streaming (for lack of better words).
The way you can address this is by setting up port forwarding in your home router. You'll want to forward port 5301 for the Slingbox. Here is an article that can help get you started:
Doing this should help fix the issue you're experiencing with the Roku and Chromecast, and should also get you better picture quality outside your home network.
Hope this helps!
Same issue, when casting to Chromecast, Gen1 or Gen2, both have problem. (with Slingbox 500)
I ran some test and found the following.
1. The disconnect issue happens on both iOS and Android version of the Player
2. If I mirror the tab from my laptop, no issue.
3. Port Forwarding to TCP 5201 already on to the Slingbox (please, Slingbox support, DO NOT tell me to forward port anymore)
4. It is not about WiFi signal issue as the router is less than 2 feet from the Chromecast
5. Also bought a LAN adapter from Google and connect to the Chromecast (so NOW the Chromecast is connected to the internet using WIRED connection), same issue, so again, Slingbox support, is is NOT about the how strong my WiFi signal is.
6. Drum roll, here is the most important finding... the drop out DOES NOT occur if the source is from Component! I can cast for HOURS if the source is Component on the Slingbox. Disconnection problem ONLY occurs when the source is HDMI.
7. Yep, Slingbox tech support, I already tried, before you asked, I lowered the "quality" to Audio only before I start "Casting" and disconnection still occurs...
So obviously, there is something wrong with BOTH of your iOS and Android app when casting to Chromecast when the source is HDMI ON THE SLINGBOX.
Hopefully they are reading this thread.
Saw a post with same problem from 2014 but no resolution. I have this exact same issue. My M1 is connected in Tampa Fl using a direct connection to 1 router, and I am in NC with Roku plugged directly into the router. After 5 minutes drops wifi. I have tried 3 devices. When I try chromecast it is hit or miss to connect and when does still drops. I am on android. Tried both lollipop and 5.01. Works perfect to android devices but not when sent to other devices.
Turned on port redirect also. Frustrating.