Utop and Ctrl+Z

I start to use the language Ocaml 4.13.1 and its tools on Ubuntu 20.04.2. Today, I tried to use utop on terminal (terminal emulator for GNOME) and I typed the command #utop_bindings;;. Next, I wanted to test the command C-z, which suspend the edition on utop. Because this command stops the job utop on my terminal, I typed the command bg, which resume the suspended job. The job utop appears, I typed any character on my keyboard, and this message appears : utop: read: Input/output error. Then utop stops. :open_mouth:

Finally, my terminal no more prints what I type : the characters are invisible. Do you have the same problem ? Thank you for your help!!!

The bg command in shells resumes a job in the background (without access to terminal input). You want to use fg.