silver_mica wrote:
Everything is through Apple. I bought the hard drive through Apple (LaCie external hard-drive). Anything software related is Apple. Like I've already said - I've been using these external drives for 5+ years - up until upgrading to Monterey. You can't change the fact that Monterey is seriously flawed. Looks like there's no fix for this massive shortcoming of Monterey. This is why you should never upgrade.
You bought it through Apple but it's a LaCie drive and how it is formatted and whether you installed any LaCie utilities or firmware for that drive is important because those things often also need to be upgraded to a version that is compatible with the new MacOS. The safest thing is to erase/format the drive when it is new, with Disk Utility (not some other third party utility), formatted as GUID and APFS. Are you using LaCie's disk utility software or package with that drive?
Again:
How did you encrypt the drive? Was it through Apple's software or through third party software, e.g. utilities that came with the external drive? What is the format of the drive (e.g. HFS+, APFS, NTFS, ExFat)?
If you encrypted the drive with third party (non-Apple) software or utilities, or the drives are NTFS and require special software or firmware to be recognized, you may need to update that software to a version compatible with Monterey.
I am using external drives with Monterey from Western Digital, Samsung, G-Drive, Seagate, Apricorn, and an old Buffalo external drive. All have worked fine so I am thinking there is something installed on your Mac that is conflicting with Monterey.
If you download and run Etrecheck, and post the report here using the Additional Text button below, people reading this thread can inspect that report (it is anonymous about you, it does show what has been installed) and hopefully quickly identify the culprit. If it is an outdated driver or firmware for the external drive, that is usually quickly fixed by getting the updated version that is compatible with Monterey.