Thank you for getting back to us.
First, please uninstall the current version of Bandicam from your PC and install the latest version of Bandicam.https://www.bandicam.com/downloads/
Next, please try the solutions below.
1. Change the resolution settings to 1080p from 2560x1440.
2. Change the video quality settings to 80 from 90.
If you still have the same issue, please make sure if you have the same issue with the H.264(NVIDIA NVENC) and let us know the result.