Easy to replicate:

Open new workbook (Cntl-N)
Press Record Macro
Name it, and assign to Cntl-Q
(have macro do something simple: add 2 numbers or something)
Now save worksheet as an add-in (either .xlam or .xla)
Close this workbook

Open new workbook
Go to options addin : and now add in the just created .xla file

Note that Cntl-Q works - but there is no way to see this macro using Alt-F8
or to see what hotkey is assigned, or to reassign the key. (Or to run it if
you didn't know it existed...)