Android - Mobile locked state accept the call & then go to mobile apps recent list, clear the all apps, at this time call gets disconnected

Hi,
In android mobile, Mobile locked state accept the call. So it takes 3 to 5 seconds to join the call.
In the meantime, unlock the phone & clear the recent apps of mobile disconnect the accepted call.
But after joined the call, It’s working fine.

How to solve this?

Thanks.