Shared cach + symlink has write permission for owner and group after "dvc add"

Hi,
I am not sure if this is a bug or intentional so wanted to check here first.
So when I configure a shared cache with symlinks and
do a
“dvc add blah.txt”
Then I see that the file that blah.txt links to in the cache is read only (as expected!).
But if another user (who is in the same linux group as me) copies the file and I execute the “dvc add” then the file stays writeable for owner and group.

eg if I (!) do :

sudo chown otherUser blah2.txt
sudo chgrp sameGroupAsMe blah2.txt
dvc add blah2

Then the file blah2.txt has “w” enabled for user and group.

The reason why I noticed this is that everyone in our group copies data into a shared folder. And only me executes the “dvc add”. But only files copied by me have the write protection-on.

So I didn’t get a “permission” error when I tried to update the files. So I think I managed to overwrite directly the files in the shared cache.

So file “blah.txt” was linked to “cache/files/md5/somehash”. And when I copied a new file via “cp newBlah.txt blah.txt” I overwrote the file in the cash (usually I expected a “permission”-error and I have to use “dvd unprotect”). So because the hash-name is wrong it doesn’t correspond to the file-content. Is there a way to fix this ? Any potential issues because of this?

Kindest regards