Possible license issue with spare 7250 placed in stack

[ericbord]

We had a 7250 POE failure on a stacked switch(2nd in 3 switch stack) and replaced it with a spare 7250.  I matched the firmware.  When I plugged in the copper SFP+ 10Gb gbics, I get a console message stating that they have been detected, but there's no link light on them and the switch doesn't add itself back to the stack.  If I do a show license on the stack I get the following:

7250(3)#sh lic
Unit License Name L3 Premium Port Speed Upgrade Speed Ports MACsec
1 l3-base-8X10G No Yes 10G 8 NA
3 l3-base-8X10G No Yes 10G 8 NA

if I do a show lic on the spare, I also get "l3-base-8X10G No Yes 10G 8 NA"

Now, this is odd.  When I do a show license unit 1, I get:

7250(3)#sh lic unit 1
Unit License Name L3 Premium Port Speed Upgrade Speed Ports MACsec
1 l3-base-8X10G No Yes 10G 8 NA

Index Lic Mode Lic Name Lid/Serial No Lic Type Status Lic Period Lic Capacity
Stack unit 1:
1 Node Lock ICX7250-10G-LIC-POD xxxxxxxxxxx Normal Active Unlimited 2

If I do a show license unit 3, I get:

7250(3)#sh lic unit 3
Unit License Name L3 Premium Port Speed Upgrade Speed Ports MACsec
3 l3-base-8X10G No Yes 10G 8 NA

My questions are

1. Why isn't the node lock license displayed when I do a basic show license command on the stack?
2. Why do I need the Node Lock ICX7250-10G-LIC-POD on the 1st switch, but not the 3rd?  
3. When connecting the failed switch #2(spare, not rma), the stack ports 2/2/1 and 2/2/3 are detected on the console, but are never lit(get a console message, but no link light) and the switch doesn't add itself back to the stack. This switch has the same lic as the 3rd switch(just l3-base-8X10G).  Is this what would happen to the stack ports if I don't have the node lock license like on unit 1?
4. If I add the node lock license to the spare, should the stack port link lights turn on and should it automatically add itself to the stack?
5. I was under the impression that the SFP+ copper gbics would run at 1Gb with the base license if there's no 10Gb license for them, but it's not - it's showing no link light at all.  Maybe the SFP+ gbics aren't able to downgrade the speed and must run at 10Gb(?)

Thank you in advance for any help!