WAD, if any is appropriate, I purchased 1 mouse and received a replacement from you folks — neither of which worked correctly after your 2 tech people took me thru all the trouble-shootings that THEY believed were necessary. Both mice did NOT work in exactly the same way. Ironically my older M510 has worked well since purchase many months ago. After last long discussion with tech person he advised that LT would send a different model as a replacement. I was put on hold while his superiors approved his solution. Now weeks later you tell me that all that effort & approval has been reversed. NOW you demand I spend more time executing the same troubleshooting tasks some of which are not practical i.e. 1) MacBook Pro 2018 has NO USB ports thus requiring a dongle adapter, 2) clean with compress air (you are kidding . Right?) IMO, Logitech is simply executing a dishonest customer service / warranty strategy by 1) by ‘forcing ‘ excessive consumer's time consumption value far in excess of the original purchase, and 2) wearing down customer patience until we "just go away."