Why does my keyboard auto create the plus ++++++ symbols when ever I bootup in Windows 10? For a better example of the problem. If I go to the start menu in Starsdock's Start10 or even with the standard search tile style in the Windows 10 search box I get this symbol ++++++++++++++++++ which is auto created when ever I get booted into Windows 10. After a bit it stops doing it. I type any other key on bootup in the search box or in a browser Chrome or Edge and I get auto created ++++ symbols going across the address bar automatically. This has been an on going issue. Any suggestions on a resolution? I also scanned my entire windows for malware/viruses and nothing showed up from all my deep rooted searches within Windows 10's files, registry and other said sectors of concern. Perhaps I need to reformat. Or maybe my Logitech G910 Orion spark is defective. Reference the screenshots if you think you know something I don't already. 
 
 

I tested in notepad and it's still doing the same thing with the symbol + even if your first choice of a key stoke is M, N, K, or P It looks like I will have to RMA the keyboard to Logitech. 
 
 

 
Try uninstalling then reinstalling the latest keyboard driver.