I bet it is trying to substitute global variables into what is between the % signs!! That is how you get a global variable into the url. I use this for different functions within rule machine. Anything between % signs is treated as a global variable. So, it is looking for the variable 20TV and not finding one. Change the names to not include spaces and use underscores instead and it bet it will work perfectly.
That's what I thought. I have had similar issues with the http get and sonos commands. That's the only time I use it. There are some other posts describing similar issues with the %20. My was to rename my Sonos devices that I called directly via a get command to a single name. Not the best way, but at least it's working.
In looking at the line, there aren't any variables being passed. The names of the Sonos devices are "Kitchen Overhead" and "Kitchen TV Speaker". It's a good theory about the substitution though. If it was consistent then no command would work with a %20 in it.
I think we are saying the same thing in different ways. I wonder if there are two % in a line (regardless of being separated by a / ), it thinks it's a variable. The only glitch I found is the lack of a packet(s) coming from the hub in that situation. So, that would negate the variable substitution idea.
@JDogg016 looks like you are using Sonos HTTP api by jishi. I use this also but I didn't notice that you could group speakers with a command. And the HTTP momentary switch will be helpful with integrating into HE. I had a WebCore rule that would turn the volume up and down when I asked Alexa but this has broke now with the new Sonos update in ST (only thing I was using ST for). I am thinking that this might be useful to accomplish this in HE and Alexa routines.
Since Alexa doesn't seem to play well with Sonos just yet, this could help to fill the gaps. I just created a HTTP momentary switch called Jane's playlist. I put it in HE Amazon Echo Skill so that Alexa could see it and now I can ask Alexa to turn on Jane's playlist. I am going to setup two switches, one that will turn volume by 5 and one that will turn volume up by 5.
Edit: This works great! I can officially take ST off line now!