Given the issue from 2 years ago with ctrl + arrow conflicting, I assume you recently made an update to change the hotkey to include shift.
Sadly, cmd/ctrl + shift + arrow is a well-known keyboard shortcut for interacting with spreadsheets to select an entire column/row from the cell you're on to the end. This combination therefore conflicts with the somewhat ubiquitous google sheets shortcut keys.
Philosophically, shift is commonly used to select a range of things, and ctrl or cmd are commonly used to go to the end of something. Beyond google sheets, I wouldn't be surprised to see other apps use shift + cmd/ctrl + arrow generally to mean "select all of the things in this direction."
Given the global nature of shortcut keys, picking shortcut keys that don't conflict with other apps obviously sucks. I feel your pain. IMO, google sheets is a significant enough app that it might deserve special treatment here. Generally, given my earlier statement, I'm not sure the cmd/ctrl + shift combination is a good choice.
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