Lenovo ThinkPad USB 3.0 Secure Hard Drive (2TB) disconnects prematurely on iOS

My Lenovo Secure Hard Drive sponatneously disconnects on its own, every single time I use it on my macbook, consistently after about 15min from the time my Mac first recognises the Hard Disk. A "Disk Not Ejected Properly" error message will pop up and the Hard Drive will power down and turn off. This happens without me ejecting or physically touching the device, while I'm still in the midst of using it (e.g. halfway working on a document that is saved on the hard drive).

The hard drive is on exFAT format. I have tried it on at least 2 iOS devices (MacBook Pro and iMac), both of which are running on the latest iOS updates. It never happens when on a PC or Windows laptop - it stays connected for hours even if the screen has gone to sleep on a Windows computer, and only disconnects when I choose to eject it.

My current work around is to save a duplicate copy of the document I'm working on my Mac, re-connect the Hard Drive, and then copy over the old file on the Hard Drive.

Choosing a different Hard Drive is not an option currently as this model is a workplace requirement and the only one that will allow me to work from home.

Would appreciate if anyone has any advice on how to stop the Hard Drive from spontaneously disconnecting. Is there some sort of driver or fix for it?