macos – Seemingly unrelated keyboard shortcuts conflicting

I got a new work laptop (old machine died) and I’m trying to set up 1Password’s keyboard shortcuts. On my old machine I had 1Password’s autofill feature hooked up to ⌘ Command⌥ Option. Today, I tried to enter that as the key chord for 1Password and was greeted with an error that ⌘ CommandC is already in use as the shortcut for “Copy” and can’t be used by 1Password.

That’s fine, I can figure out another shortcut to use in the short term, but I’m very confused as to why ⌘ Command⌥ Option maps to ⌘ CommandC. I have confirmed that this mapping does exist/work properly, ⌘ Command⌥ Option does copy text on my machine, but it’s a brand new computer and I didn’t set up that override, so I’m very confused as to what’s happening.

Any explanations would be appreciated.