There are no bad reasons for taking a pause during your viva.
A pause to check you’ve heard your examiners correctly. A pause to get your thoughts in order is helpful. Checking a detail from your thesis is a useful beat of silence.
The pauses in the viva aren’t limited to your side of the table or the Zoom call. Your examiners may have to read their summaries or make a note for later. They may need to check between them to see who will speak next.
The pauses in your viva are the punctuation for the discussion. Like punctuation in a book they are just as necessary.
Pause, think and respond. Pause, check and ask. Pause, note and consider.
Silence isn’t always comfortable but pausing in the viva is never bad.
Take your time.