Conflicting keyboard shortcuts for tab navigation in Chrome Dev on Mac

I set "⌘+ ⌥ + Left/Right" as the shortcut to move window to Left or Right side of the screen. It seems to work well, except in Chrome Dev, where upon keypress, the [Tab] menu shows a flash before the app brings tab before/after the current one.

But the keyboard shortcut for it has always been "(⇧+) ⌃ + ⇥".

I feel like this is just the usual accessibility/versatility compromise between Google and MacOS (Like `Fn + F12` activates Developer Tool though the keyboard shortcut in the Menu is `⌥ + ⌘ + I`).

How to even override a keyboard shortcut that is not listed?

[Re-Titled by Moderator]

Original Title: "⌘+ ⌥ + Left/Right" triggers [Previous/Next Tab] on Chrome when the menu bar shows "(⇧+ )⌃ +⇥".