Error message when installing ferrumgate

when installing ferrumgate on a vps with debian 12, I get the error message "sh: 101: ulimit: error setting limit (Invalid argument)"

The script sets the following lines in my /etc/security/limits.conf

root soft nofile 1048576
root hard nofile 1048576
* soft nofile 1048576
* hard nofile 1048576

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Whe I manually type, I get the following results:

ulimit -Sn > 1024

ulimit -Hn > 524288