First of all, sorry for the late explanation on this. Based on the information you provided back in your reply it was clear you didn't exploit these vulnerabilities, hence you couldn't submit a valid PoC which resulted in the reports being rejected. Now, why do we do this? Because CTF365 is a training platform, each host on our networks is carefully configured to allow various levels of exploitation that can generate a good PoC to which we can award points. If we award points for reports without valid PoCs (even those with valid vulnerabilities cited), this will encourage people to take the easy route, ignore the exploitation phase and just submit their scanners results to us, which isn't what we are trying to help people learn through the platform.
If you find a vulnerability that you absolutely couldn't exploit, then either it is not the vulnerability that would help you penetrate that specific host or you are doing something wrong, go back, do more enumeration, and be more persistent.
As for your question on why was the first report accepted but not the following seven, it happened by mistake, and we will leave it in its current state (Accepted) until we decide what to do in such situations.
To avoid these issues in the future make sure to read (and adhere to) our vulnerability reporting guidelines on the following links: