How can I fix random voice control activation on iPhone 15 with iOS 18.2.1?

My voice control getting triggered randomly even though it is set to off under accessibility settings. It happens randomly and there is no specific pattern. It waits for my input and if none provided, it switches off. But it is very annoying.

iphone 15

ios 18.2.1

had issue with older versions of software as well. Tried all possible approaches available on web. Nothing helped.

[Re-Titled by Moderator]