Encrypted External Portable HDD Not Accessible on Macbook Pro M1 with Sonoma 14.5 macOS

I have Sonoma 14.5 macOS on Macbook Pro M1 from 2021 and have external HDD (exFat) which has encrypted data. This Disk was accessible earlier but now it doesn't mount on to drive. I am sure the portable Disk is in working condition as I have tried it on 3 Macbooks with no success. I read lot of posts about it but was not able to find a solution.

Here how it used to work earlier: I have a Western digital lock on my portable HDD. Once connected to MAC, I used to unlock the drive and then the partitions would start showing up in the Finder.

Now: I can unlock the WD drive but the partitions don't mount and errors out with message: "A problem was detected with the disk that prevents it from being unlocked"

Did anyone find a solution to it? Any suggestions or workaround are much appreciated.

Note: I don't have windows machine. I tried on other MaC which has Monterey macOS, but the issue persist

Thanks so much