Make sure the bug also happen when Details! is the only addon enabled.
Only addon enabled.

Game and Details! version
VWD 12044 Release 10.2.0

Describe the bug

• Steps to Reproduce (what did you do to make the bug happen):
  Use the following commands in chat:
  /dump Details:GetSpec("player")
  /dump Details:GetSpec(UnitGUID("player"))

• Result (what happens when you follow the steps above):
  Nothing is returned

• Expected (what you think the expected behavior would be when following the steps):
  I should get a spec ID, per this API documentation

• When the bug started (a date, wow path release, details update, etc)?
  I haven't been playing for about half a year but I had a WeakAura that used to use this function to get spec IDs and it's no longer working as of at least 11/10/2023

• Additional information:
  I am able to /dump Details and read the methods/variables successfully, so Details is at least accessible.

Lua Error
Post here lua errors, if you aren't getting any, use /console scriptErrors 1
No LUA errors

Screenshots
Post images of the bug if necessary.

Other Information
Has the method to grab spec IDs changed? The GetSpec call for sure used to work in the past.