I encountered the same issue, and for me, it was related to how I structured the logic in my React component. Specifically, I had the Google login initialization, One Tap prompt display, and login button rendering all inside a single useEffect hook. Once I split the logic into separate useEffect hooks for each part, the One Tap modal started dismissing as expected—without needing any manual intervention.

Interestingly, I found that the issue of the modal not dismissing was only present in Chrome. The modal dismissed correctly in other browsers, but not in Chrome. Splitting the logic into separate hooks resolved the issue in Chrome as well.