I have had a similar problems with Garageband when I was using it on my Mac, and I solved it performing a reset in the app. Go to Settings > GarageBand, then tap Reset GarageBand. This should solve the issues.

As now I have had to shift to windows, I am looking for some solution to run Garageband on my windows desktop. Do you know any working methods for it?

Thanks @richardx49, I will try it. For Windows, You can use any PC emulator such as VWware to run garageband app. I foung this article where complete steps are well explained. SO, you can refer to that.

This exact same problem i am also facing garageband app. After that I uninstalled it and reinstalled it. Hope it might also works for you.

Re installation will solve your problem.

Reinstall Garageband on your Pc.

I don't thing it will!