There is an automatic which will start the downswing after a certain time in upswing. It may be 15 s(?)
On PC, it may also be the problem of an empty battery in a cordless mouse.
Good thing is, the swing will not perform without further action during downswing, and there is no limit in attempted swings, even if the program reminds you to do the second click.
Just let it pass through and try again.