All drives in active state,but jobs in queue state

Still not answers to all questions....

1. Why are some tape drives shared and some not?
2. For which media server(s)/STU do you see queued jobs?
3. Please show us all the text in Details tab for some of these queued job.

The device and STU config seems 'strange'.

3 drives in robot 1 are shared and the rest dedicated to media servers.

We also see that some drives are not configured on any of the media servers - 
Drives 4 and 6 in robot 1
Drive 2 in robot 0

Why are these drives 'missing' from device config?

This is what I see in device and STU output:

Robot 1:

CLBBACKUP01 Robot 1:
Shared:
drive    -    1 hcart2    9      UP  -          IBM.ULT3580-TD5.004  /dev/nst3
drive    -    2 hcart2    7      UP  -          IBM.ULT3580-TD5.006  /dev/nst2
drive    -    4 hcart2    3      UP  -          IBM.ULT3580-TD5.007  /dev/nst0

non-shared:
drive    -    2 hcart2   11      UP  -          IBM.ULT3580-TD5.001  /dev/nst9 
drive    -    3 hcart2    5      UP  -          IBM.ULT3580-TD5.002  /dev/nst8 
drive    -    4 hcart2    1      UP  -          IBM.ULT3580-TD5.003  /dev/nst7 
drive    -    8 hcart2    8      UP  -          IBM.ULT3580-TD5.005  /dev/nst5 
drive    -   11 hcart2   12      UP  -          IBM.ULT3580-TD5.008  /dev/nst0 
drive    -   12 hcart2    2      UP  -          IBM.ULT3580-TD5.009  /dev/nst1

STU:
Label:                CLBBACKUP01-hcart2-robot-tld-1
Number of Drives:     12
Max MPX/drive:        4

So, in STU config, you have 12 drives configured for CLBBACKUP01 in robot 1
but only 9  (3 shared, 6 non-shared) tape drives configured in NBU??
 

CLCLMODBDP01 Robot 1:

Shared:
drive    -    5 hcart2    9      UP  -          IBM.ULT3580-TD5.004  /dev/nst4 
drive    -    9 hcart2    7      UP  -          IBM.ULT3580-TD5.006  /dev/nst3 
drive    -   10 hcart2    3      UP  -          IBM.ULT3580-TD5.007  /dev/nst2 

non-shared:
drive    -    0 hcart2   10      UP  -          IBM.ULT3580-TD5.000  /dev/nst4
drive    -    4 hcart2    3      UP  -          IBM.ULT3580-TD5.007  /dev/nst0

STU: 

CLCLMODBDP01-hcart2-robot-tld-1
Number of Drives:     5
Max MPX/drive:        1

Here STU config matches device config:
STU config, you have 5 drives configured for CLCLMODBDP01 in robot 1
and 5  (3 shared, 2 non-shared) tape drives configured in NBU.
No Multiplexing configured?
 

Robot 0:

CLBBACKUP01 :
drive    -    1 hcart2    4      UP  -          IBM.ULT3580-HH5.000  /dev/nst11
drive    -    6 hcart2    1      UP  -          IBM.ULT3580-HH5.001  /dev/nst10
drive    -    7 hcart2    3      UP  -          IBM.ULT3580-HH5.002  /dev/nst6 

STU:
Label:                CLBBACKUP01-hcart2-robot-tld-0
Number of Drives:     4
Max MPX/drive:        8

In STU config, you have 4 drives configured for CLBBACKUP01 in robot 0
but only 3  tape drives configured in NBU??
Drive 2 missing from config....
MPX seems to be excessive.
 

You need to fix the configuration as a start. You cannot have more drives in STU config than devices on each media server.

You also need to have another look at amount of devices added to CLBBACKUP01. 
If these are physical tape drives, there are way too many for one media server to use efficiently.