Your silence in a meeting usually gets counted as a yes. If you disagree, say it once and say it clearly.

Groups move on consent and read quiet as consent, because nobody has time to check each face. Your private reservation is invisible, and afterwards it counts for nothing, since the decision was made with you in the room not objecting. That is not unfair so much as how rooms work.

If you disagree, say it in the meeting, plainly and once. You do not have to argue it to the end or win. Having it said means the group decided knowing, and if it turns out badly you are in a position to help rather than to have been quietly right.