Our older child had been learning C++ for a little over a month when the screening notice came. On April 21 we were told there would be a selection process; around April 26 there would be a computer-based test, and anyone who did not pass would stop going to the lab for further lessons.
On April 22 the child started working through problems—five of them on the computer. The schedule before that had not been arranged well. I had not pushed for daily practice either, and a lot of time had gone into playing Identity V.
The old line held: without the work, there is no return.
On the morning of April 23, the teacher sent word that there would first be a school-level screening, then a district-level one. The test happened that afternoon: three problems, 300 points in total. Our child scored 100 and was out. There would be no more learning with that teacher.

Self-study is the only option now. I will keep after the child—and learn a bit myself as well.
I don't know whether there will be another chance in sixth grade. There is also a district-level “Mayor's Cup” later; apparently anyone can enter, but I don't know the details. It feels like things change as quickly as the news around Trump. Still, opportunities only go to those who are prepared. You have to be ready and not let up.
The one good thing about this is that the frustration came at the right time.
It is like investing. Making money on your first attempt is not necessarily the best thing. Suppose your first investment gains 30–90%, you don't sell, it drops to -10%, and then rises to 60%—the numbers are made up, just to make the point. You taste the sweetness and also learn to respect the market. That kind of case is probably not common. If the first attempt fails, some people never invest again; some go and cram knowledge; most give up. Maybe that person read Munger's book and remembered only this: “With big dangers, my attitude is to stay as far away as possible. Others get as close as possible as long as they don't fall in. I think that's too risky; I don't want to do that.” If the first attempt earns a lot, a person may invest more and lose more; they may clear out when they are not losing and leave; or they may become a professional trader, so that situation is not so bad.
Not abandoning and not giving up seems to have some effect at any time. Keep working.