fail to access files on an external disk

Hi everyone,

I have a MacBook M1 Pro with Sequoia 15.3.2 and for the first time in more than 20 years (of Mac) I have a problem that I can't solve.

Normally I use an external HD as a archive and for Time Machine (a common 4 Tb Toshiba formatted in APFS), for this purpose I created two "containers", one of which, the archive one, is encrypted.

Until a few months ago as I connected the disk the Time Machine icon immediately appeared and then the other one of the archive disk, I was asked for the pw and I could access regularly.

Now this doesn't happen anymore, after connecting, the TM icon quickly appears, then, calmly, the archive disk icon, there is no trace of a password request, if I try to open the archive disk folder the "load wheel" appears and stays there indefinitely (once even about 3 days before I got bored), the disk works continuously and even the TM backups are affected by slowdowns, in fact they fail at all if I don't eject the archive disk.

These are actions that I have taken to try to solve the problem:

- changed cable and port several times

- changed Mac (with the only result that it asks me for the password)

- repaired disk (several times) both in "normal" and safe mode

- tried alternative Finders (Forklift and Commander one).

The strange thing is that, using Easy Find and, for example, searching for all the jpg files, they are all there and I also see the preview, unfortunately when I ask to view them in the Finder everything freezes and I don't see anything.

There are a couple of Tb of important stuff especially since the original HDs are in a container that will reach me, in a few months, where I currently live.

If you had the patience to read and have any ideas on how to solve it, I thank you in advance.