U3423WE, webcam, KVM7321 keyboard/mouse lag

Any ideas on how to eliminate Dell keyboard/mouse lag on a Dell USB-C Hub U3423WE with a webcam?

I recently purchased the UltraSharp USB-C Hub monitor model U3423WE. I also purchased the "Dell Premier Multi-Device wireless keyboard and mouse" KM7321W which supports KVM switching. I use two laptops, and this setup was designed to let me connect two laptops to the same monitor and letting them share the keyboard, mouse and other devices (webcam) via the built-in KVM switch in the monitor.

The problem: After getting things setup, the keyboard and mouse work fine and I can swap between each laptop using a hotkey. The problem is when I plug in a Logitech Brio webcam to a downstream USB port on the monitor. At various times, the keyboard and mouse become extremely sluggish. Actually using the webcam from either laptop does not cause the issue. Just having it connected to the monitor creates this intermittent lag. It gets to the point where I can type a few words and wait 15 seconds for them to appear on screen, often with letters missing or doubled. As soon as I unplug the webcam, keyboard/mouse are fine. 

Some details:

I made sure all drivers for the webcam and Dell devices are current. The wireless keyboard/mouse are connected to a downstream USB type A port on the monitor hub. The webcam is connected to another downstream USB type A port on the monitor. I use the latest Gen 2 USB cables.

I noticed when I first plugged in the webcam to the monitor, the Dell Peripheral manager won't recognize or even detect it for starters. So I plugged the webcam directly into each laptop to get it working on both. Still, Dell peripheral manager would not detect it, but since the webcam works I don't know how much this matters. Dell peripheral manager recognized the Dell Keyboard/Monitor devices, but perhaps it does not detect non-Dell devices. 

I read somewhere that that Dell does not recommend placing other downstream USB devices adjacent to the keyboard/monitor dongle. I am guessing this is to avoid interference. If that is true, then it limits the capabilities of this hub monitor - the whole point is to use the monitor like a KVM/dock. So I moved the mouse/keyboard dongle to the far right USB port (next to the ethernet port) and moved the webcam USB to the left-most USB type A port. This seemed like an improvement - I didn't experience mouse/keyboard lag until the next day. It seems I can unplug the webcam and plug it back in and things are fine for a while. But this is not the long term solution for me. The only reliable option is to plug the webcam into each laptop when needed, but again, this is why I purchased a USB-C hub monitor.