I have a MacBook Pro 2016 and a my passport for mac hard drive which stopped mounting. Also, try using different cables as some are able to carry more power than others. If it’s your case, the beeps should be gone after the disk gets enough power. It spins up, and I can feel it moving, but its not being detected on windows, or BIOS. Its is not being recognized in my macbook.
However, users may sometimes encounter problems like Seagate hard drive not detected or Seagate hard drive not recognized. Seagate hard drive light on but not detected mac In most cases (in fact over 97% of them.