Re: XPS 13 9370 Ubuntu full disk encryption
I have got good news: it is working !
I have succeeded creating the new Dell Recovery USB key containing the fix by copying the deb file on the SSD recovery partition and asking again the creation of the Dell Recovery USB key.
Then, I was able to reinstall Dell-Ubuntu and create a pass-phrase "rrrrr" that is recognized at following boot.
If you don't have a QWERTY keyboard when defining the pass-phrase, you will probably encounter an issue when switching Ubuntu in your regional language.
So, my advice is to create a simple pass-phrase with characters compatible with QWERTY position, then change Ubuntu regional language. Boot from standard Ubuntu Live also configured in the regional language and change the pass-phrase from Disk application.
It worked for me.
Thanks for your support !