Hi there efarnese,
I understand that you originally had problems with Siri going off, now you're having problems with voice control going off randomly. After looking around the Apple Support Communities, it looks like you aren't the only who's having the problem. I also did find that another user has stated that if you do turn off Siri, Voice Over will take over the role of Siri. Please follow these troubleshooting steps exactly as they're listed. Go through all of these steps until you found a step that helps resolve your problem, or you have went through the entire list of steps and are still having problems. In the steps I've provided some information on what you should do, and references to knowledgebase support articles from Apple if you need help following the steps.
Originally before when you had Siri on, did you happen to have your iOS device plugged in at the same time? If you did that might've been why Siri kept going off. To fix this follow these steps: Open the Settings app > Scroll down and tap on General > Tap on Siri > Toggle off Allow "Hey Siri."
I hope this helps!
🙂