The same thing happened to me and I was about to give up until I decided to just cycle through all of the USB cables in my house. Eventually I found one cable that will successfully connect the MKR 1010 to my computer.
Even other known-good cables that successfully connect other devices failed to work on the MKR wifi 1010; but for some reason this braided cable (likely the most expensive one that I own) works 100% of the time.
I hope that helps!