See
https://tex.stackexchange.com/questions/685511/beamer-inserts-line-break-at-strange-place/690742#690742
As in the above discussion, a workaround is to insert a blank line before the quote env.
As with this other issue
#530 (comment)
having to insert a blank line before a list-like environment is unusual to the user of LaTeX.
See
https://tex.stackexchange.com/questions/685511/beamer-inserts-line-break-at-strange-place/690742#690742
As in the above discussion, a workaround is to insert a blank line before the
quoteenv.As with this other issue
#530 (comment)
having to insert a blank line before a list-like environment is unusual to the user of LaTeX.