Trying to better understand how Bash select statement variables work

I’m finding that when using select statements in Bash, I can set
PS3="to whatever I want" and it will work globally on all select statements.

But, if I set COLUMNS=1 it doesn’t work globally. I have to set it in each function where a select statement is being utilized, and the main code block which doesn’t sit inside a function at all I have to move the declaration COLUMNS=1 to immediately before the opening select statement.

export COLUMNS=1 not working either.

Is there a reason eluding me for this?