Crypted partition on Ubuntu becomes readonly after browsing

[Jean Nem.]

Hi.

I got the following problem : I'm using a big 1.8To partition in FAT encrypted with veracrypt for my personal files.
When I mount the volume, everything is fine.
After some time browsing or working on the partition (or after acessing some particular folders within it, I could no say), it becomes fully read-only, I cannot modify anything on it.

So I have to dismount and re-mount the volume to continue working, until it hangs again.

What could be the cause of this problem ?

[Jean Nem.]

Hello.
No idea ?
Well, I went a little further in the analysis of this problem : Maybe it's related to the trash :
I'm unable to delete anything put in the trash that was initially in my encrypted volume (with the UI, "rm" shell script, utility "trash-empty"... ).

The error is
*"Error during deletion
You do not have the sufficient permissions to delete file "xxxxx"
Failed to delete the item from the trash" *

If I try to delete something in the trash, than the encrypted volume content becomes locked, and I have to dismount partition.

[Jean Nem.]

Thanks for your help.
It seems I've finally found a solution : perform a file system check on unmounted DOS partition allowed me to correct errors and empty my trash. Now the system does not lock the veracrypt volume anymore.

sudo apt install pmount
pumount /dev/dm-0
sudo dosfsck -r /dev/dm-0