ServeRAID and tape drives compatibility

[ATENDE]

I had this configuration: IBM xseries 330 with ServeRAID 4LX and firmware version 4.84.
I created an array using the 2 disks and it works.
Then I attached a Tape enclosure from Exabyte with 4 drive to the external SCSI port of ServeRAID and it works. I can backup and restore data.

Then I upgraded the firmware, the driver and the ServeManager first to 5.11 version then to actual.
And it works.

Now I want to remove the tape enclosure and attach it to a dedicated SCSI controller to use two channels as described by the vendor.

If I power off the server and the tape enclosure, I remove the SCSI cable from the external port and I power on again, it cannot boot.
The system stops and the ServeRAID controller display

F2 to view details
F4 retry
F5 accept new settings
F10 ignore new settings

If I press F2 I view the tapes are in fault (OK, I disconnected them), if I press F4, F5 or F10 the system does nothing.
It doesn't start and, to boot, I must power off the server and reconnect the enclosure.

I read in IBM site, ServeRAID 5 and 6 not support tapes on external port, but I read nothing on 4LX.
Do you know if can I remove the enclosure and the 4 tape drives from the ServeRAID configuration?

Greetings