KB740 keyboard randomly switches bluetooth connection and will sometimes enter long strings of the same character

Several people in the office use the keyboard KB740 via Bluetooth.  I get reports from them where at random the keyboard will switch between the bluetooth connections (it has two) or that it switches to try to use the USB dongle connection (which isn't used so is physically under the battery cover).  

What they also report from time to time is that when typing the keyboard will sometimes seemingly hold down the last key they pressed - its not physically held down but it will automatically enter a very long row of the same character.

We use Dell laptops running Windows 11 and have the Dell Peripheral Manager installed so the firmware is kept up to date.   

If it was just one person I may suspect a faulty keyboard or something they are doing - but I get this reported by several people.  I've also experienced it.