Still getting 'disk not ejected properly...etc' macOS Catalina, Big Sur and Monterey Beta.

'disk not ejected properly...etc'

Has anybody ever discovered a reason for this perpetual and repetitive message?

Even though none of the offending disks has been touched.

I used to think it was using a non powered hub or drive, way back in OSX Mavericks, but my current 4TB local drive, USB3 to port on rear of iMac 14,1 - in a powered drive case, connects and disconnects for no reason - untouched by human hand and never actually unmounts

I have had successive OS on various machine/OS combo, since 2007 when I changed to Intel iMac

this began happening randomly at first

Come to think of it Firewire never did this.

**** If I boot the same machine into Linux IT NEVER DISCONNECTS. ****

I come to the conclusion over many macOS and Mac hardwares that it may be a software glitch ?triggered by?????

The other external drive 'LOCAL BKP' never disconnects, also USB3 to rear port unpowered?????

Any sensible suggestions would be welcomed.