Let's start with the basics. Does going into the sonos device in the Hub Web UI and putting something in here:
and clicking Play Text, does that actually work on your Sonos?
Rule Machine uses the same method, so if this doesn't work, then its not RM, its something with the sonos speaker directly. Possibly an IP address change?
Single rule with a single sensor TTS work
I have a group with 3 sensors, if one is opened, It does TTS
If one remains open, and you open another, it does not TTS
Adding a group of like 15 sensors, does not work.
When you use a Rule, for it to take action the rule-truth must change. So if the rule is already true because one of the sensors is open, opening additional sensors will not cause anything to happen.
You should use a Trigger, not a Rule for what you want to do. With a Trigger, each trigger event will cause the action. This is what you are describing.
Whenever there is a Rule with a single Condition (your case), and there are only Actions for True (also your case), that should be a Trigger.
This is all explained in the Rule Machine Introduction, here: