Airpods Pro 2 Custom Transparency Mode Keeps Turning Off

(Using my iPhone 14 Pro Max with iOS 18.1, together with AirPods Pro 2)

When I set a Count Down Clock timer on my Apple Watch Ultra 2 (for example, 1 minute) and the timer expires, the AirPods Transparency Mode stops working and the check mark disappears in the Headphone Accommodations menu. If I reselect Transparency Mode ON and set another Count Down timer it happens again when the timer sounds. I hope this helps find a solution to the Transparency Mode dropping issue. 

Note: setting a Count Down timer on my iPhone itself will not inhibit the Transparency Mode when the timer expires!