We have a stack of x460-48p (gen 1 NOT gen 2) running code 22.214.171.124 patch 1-3. We had one slot reboot periodically (had tried replacing the power supply, power cable, stacking module and stacking cables) but it still reboots. So today we replaced the unit with a spare from stock and plan to RMA the defective. We got the code and partition setup properly (we have lots of practice with this exercise...... hooked up the replacement to the stack, but it won't join the stack so that we could give it a number and join the group. When we do show stacking on the existing stack, the new mac never shows up in any way. We tried unconfiguring switch all on the replacement switch and rebooting and even replaced the stacking module thinking maybe something was wacky with that. The code and partition is correct, there are no core licenses causing issues. The only thing that looks different with the replacement switch is the bootrom, it's newer at 126.96.36.199 versus the existing stack at 188.8.131.52 Could that be the cause of our issue? We had to get the switch band-aid connected b/c school day was starting so I wanted to see if there are any ideas that we can try to get it properly setup. There were no error messages on either the existing stack or the replacement device. And as mentioned we replace defective devices all the time so this is a head scratcher. Thanks in advance for ideas.