Shift key keeps selecting (android)

What I’m trying to do

Find out why the shift key selects without me pressing it.

Things I have tried

Looked in documentation. Searched the google. Consulted the oracles.

Question:

I noticed that when I copy text in order to paste later, it first downcases the selection.

This is because when I select text, the shift key becomes selected, so I automatically press the shift key to deselect it. That downcases the selection.

Why does the shift key become selected?

Can you think of any other surprises like this I might discover?

Hmm. This is no longer happening…

Never mind.