I am more than happy to guide you in the right direction. I understand that you are having issues with your Logitech G602 mouse and external Apple Keyboard intermittently disconnecting during normal use. Thank you so much for using Apple Support Communities! Is there something being slowly corrupted in my OS 10.15.3?

If left 'un-booted', then it gets so bad that sometimes the pointer will not move at all for2-3 seconds, then 'catch up'. I have tried unplugging everything from the back of the iMac, then reconnecting only the keyboard and mouse to the back of the iMac.good for a while (time always varies depending on the amount of usage). The Apple keyboard is plugged into a rear-of-the-iMac USB port. The connections are this: Apple Mouse to one of the side USB ports on the Apple Keyboard. I have even tried switching out the Expert Mouse altogether, replacing it with the original wired Apple Mouse.no joy. It is doing this as I write this - and I am using the default Apple Mouse driver. Then the stutter motion started up yet again. I re-booted yet again and all was right with the world - for a while. Then the mouse pointer began displaying that jerky-jerky, stutter motion again. What remained was the native Apple Mouse Drivers. Anyway, my experimentation entailed completely removing all things Kensington, then I re-booting. I wasn't sure if the problem started with the Mac OS upgrade to 10.15.3 or the Kensington upgrade to 2.1.11. I mistakenly upgraded my Kensington wired Expert Mouse to their latest software (upgraded from, I believe, TrackballWorks v1.5.0 to the 'new-and-improved' KensingtonWorks 2.1.11). My iMac (Retina 5K, 27-inch, late 2015), 3.2GHz Quad-Core Intel Core i5, 24 GB 1867 MHz DDR3 RAM with the OS: Catalina OS version 10.15.3. Ran Diagnostic check that came back clean.I feel that my new MacBook Air is a big paperweight at this point. Looking for additional suggestions to fix or troubleshoot the issue. Things that I have tried to resolve the issue. Granted I only was running Catalina for 2 days with the MacBook Pro 2019. Using the same USB hub and external devices I did not experience this issue with that configuration.

This MacBook Air has replaced a late 2019 MacBook Pro that was running Mojave and then Catalina 10.15.4 for the last 2 days of use. I have attached a screen capture of what the USB device looks like normally when things are working correctly. Disconnecting/reconnecting the USB Hub does not resolve the issue. The USB 2.0 HUB under System Information->Hardware->USB completely disappears until the MacBook is reported. At random times during the day (2-3 times a day) my Logitech G602 mouse and external Apple Keyboard will stop responding completely and only a reboot will restore functionality. I have an external USB hub connected to one on my Thunderbolt 3/USB-C ports on my MacBook Air early 2020 model running Catalina 10.15.4.

Imac usb hub