Using External Monitor & Camera with Macbook Pro

I have a Macbook Pro 2019 with decent spec. I plug it into a normal 21" external monitor. I also use an external webcam for my video call (Logitech C920e). This is a very normal workflow. But the problem is, every time I have a video call, specially if I do screenshare, the CPU usage goes 100% and everything comes to halt. My audio and video falls out of sync, and everything becomes irresponsive. When I check the Activity Monitor, it's just the system using that mach CPU. There is no special process causing this. I've turned off Software Acceleration in Chrome, but that's not the problem. The issue still exist. Also, I have the same problem if I do video recording using OBS. Any idea what is the problem? PS: The MBP specs are 2.4 GHz 8-Core Intel Core i9, Graphics: AMD Radeon Pro 5500M 4 GB Intel UHD Graphics 630 1536 MB, 64GB RAM