Logitech K480 Bluetooth Keyboard with iPadOS 14.5: When cursor is at end of line in Notes, pressing the up key twice skips to top of document

I have a Logitech K480 external bluetooth keyboard that I use with my 7th generation iPad (note that this question is listed under the 6th generation iPad because there doesn’t seem to be a 7th generation iPad option?) with iPadOS 14.5.1. I have noticed that when I am typing in the native Notes app, if the cursor is at the end of the line pressing the up key twice will skip the cursor back to the start of the document. Subsequently pressing the down key once will return the cursor to the original position. This seems to happen no matter where in the document the cursor is originally situated, and is quite annoying because it makes it difficult to rapidly move up a document (and the K480 keyboard and iOS don’t seem to have a ‘page up’ or ‘page down’ function to rapidly scroll through documents). This behaviour also occurred with iPadOS 14.5 before the most recent update. 

Is this a feature of the iPad with iPadOS 14.5? Or is it a feature of the Logitech K480 external keyboard? Can the behaviour be customised (or, failing that, stopped)? Is there any documentation of this feature?