While the minibuffer window is active, attempt to switch buffers in
an ordinary window like so:

emacs -Q
M-: (setq enable-recursive-minibuffers t) RET
M-x C-x o C-x b foo RET

In emacs 27 and earlier, that will switch the buffer in the main
window to the new buffer named "foo", but in emacs 28.2, it generates
a bogus "user-error: Cannot switch buffers in minibuffer window".

I get the same results with -nw.