Public calendar link can be invisible

How it was found

Hello, I was working on the calendar settings. Where I saw, there is a public calendar link creator box. Usually people put their username in that box. But I was tired to do something. I know the calendar link can be unlisted as public. But the things I found, I can make my calendar link public and invisible at the same time. Here's my PoC:

1. Search for a existing file in https://cal.mixmax.com. (for testing purpose, I choosed robots.txt)
2. Now I have put my username as robots.txt {F200314}
3. Now click on View, https://cal.mixmax.com/robots.txt will open, which is a existing file link. But main purpose was viewing my calendar. But in this situation, my calendar is totally hidden by that existing robots.txt file.

Already existing filename should be unavailable for the calendar link creation. NB: I am removing my link as robots.txt because I want you to investigate in this issue. Thanks, Faisal Ahmed