Session terminates without reason

I have a strange behavior happening and I cannot pinpoint it’s origine.

I have two page 1 & 2, each on containing a block A & B. Work fine in dev and prod

I need to remove page 2 and move block B after block A on page 1. Work fine in dev but in prod the session terminate instantly.

If I move back block B to page 2 everything is back to normal.

Does anyone have an idea about this behavior?

Both server have the same configuration (scriptcase.host)

Regards

Version 9.10.023