Same issue, when casting to Chromecast, Gen1 or Gen2, both have problem.
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.
So get this, for several days the Chromecast 2 was scrunching the screen and disconnecting.
Then it could not connect at all (no scrunching).
Then I gave up after hours and days of troubleshooting.
Then my wife uses the slingplayer with Chromecast 2 without knowing any of the issues I had been experiencing in prior days or knowing that it does not work.
And it works for her!!!!!! What the %&$!!
This tells me it was something on Slingbox side because I touched nothing on my side for 2 days. In fact I wasn't even around to touch anything.
Sling should investigate what was going on whether it was them or even Comcast or Google. Right now Sling either knows or has no clue. It could be Sling is doing it to us without even knowing it is happening. This isn't the first time things just fix themselves on their own. It tells me the right hand doesn't know what the left hand is doing. Sling needs to understand and get control of what is happening and why. And then LET US KNOW WHEN YOU MAKE CHANGES THAT MIGHT IMPACT US.
A friend with a Chromecast 1 who was having same issues as me also reported that their Chromecast started working out of the blue.
Scrunching on Chromecast 2 has begun again (as of Tuesday 1.19.2016). I did not have the issue for past 4 days.
Today's (wednesday) scrunching is different, it happens for a minute then goes away. It is not disconnecting me from Chromecast 2. Further evidence this is something to do with Sling's Servers.
It kind of seems like somebody is working on the issue. Of course Sling will never tell us!