You had the point. You know the subject better than half the people in the room. And by the time you'd assembled the sentence, the conversation had moved on and saying it would have been strange. This is one of the most common experiences professionals have working in a second language, and it is not a confidence problem.
What's actually happening
Three things at once.
You're listening in a second language, which takes more processing than listening in your first. You're composing a response in that same language while still listening. And you're monitoring the conversation for the moment to enter, which in a fast meeting is a window of a second or two.
Any one of those is manageable. All three together is the reason the window closes while you're still on the second task.
Why fluency doesn't fix it
People assume more vocabulary will solve it. It helps a little, but the bottleneck is usually speed and timing rather than knowledge.
Perfectionism is the other half. If the sentence has to be correct before it leaves, you've added an editing step to a process that already has no spare time. Colleagues speaking their first language are not editing; they're starting sentences before they know how they end.
What actually helps
Speak in the first five minutes. The longer you go without speaking, the higher the bar becomes for what's worth breaking the silence for. A short early contribution — agreeing with someone, asking a clarifying question — removes that.
Prepare one thing. Not a speech. One point you intend to make, phrased in advance. Having it ready means you're not composing under time pressure, and it often leads naturally into the rest of what you want to say.
Learn the entry phrases. Can I add something here? · Just to build on that · Before we move on, can I ask — These buy you two or three seconds of floor while you assemble the actual sentence. First-language speakers use them for exactly the same reason.
Interrupt earlier than feels polite. In most English-speaking professional cultures, waiting for a gap means waiting indefinitely. The gap you're looking for frequently doesn't come.
The thing to stop doing
Rehearsing the sentence silently until it's perfect. By the time it is, the moment has gone, and you've spent the meeting writing instead of listening.
A slightly rough contribution made at the right time does more for you than a flawless one made never.
Where practice comes in
This is specifically a speaking-under-pressure skill, and it doesn't develop from reading, listening or study. It develops from having unscripted conversations where you have to respond before you're ready — which is uncomfortable, and is the whole point.