If we try to upload a single test case file by clicking the New button, when we try to upload a file, something reloads and the window disappears and thus the test case can not be created.
Video link for better understanding: https://drive.google.com/file/d/1xtdQkncVC-mY-NfAhZ0Tmr8W1Ff3ovf1/view?usp=drivesdk
PS: The video is taking in Android, but I found the same problem in PC too (browser - Chrome).