I’ve been using a 6TB Thunderbolt for 3 months without any problem. Got a second one and daisy chained to make a backup of the first one but I can not copy files to it. Macbook Pro ejects it after 10-15 minutes copying starts.
Called Apple, and WD and no solution. It does not eject while NOT beeing written on and it is NOT a defective unit because I replaced it twice. This is the third drive doing it.