I found a solution for my environment:

• I'm running Ubuntu 18.04.4 LTS
• Opera rel. 114.0.5282.21 (snap version)
  I added --lang=it (my preferred language) to the command line used by opera launcher
  
  Great: it works fine!!!

Now I will test Ubuntu 24.04.4 over my laptop and over VMVirtualMachine, but I'm optimist ...

I just tested over VMVirtalBox - 24.04.1 LTS (Noble Numbat) 64-bit:

OK!!! it works

Bye

I found a solution for my environment:

• I'm running Ubuntu 18.04.4 LTS
• Opera rel. 114.0.5282.21 (snap version)
  I added --lang=it (my preferred language) to the command line used by opera launcher
  
  Great: it works fine!!!

Now I will test Ubuntu 24.04.4 over my laptop and over VMVirtualMachine, but I'm optimist ...