fzf-tmux popup border not rendering properly

[damnskippy]

Somehow with fzf-tmux popup, border is not getting rendered properly. Not sure if there's an issue in my setup/environment., or if I need to update tmux. Thought I'd check here to see if anyone is seeing this.
Thanks.

$ fzf --version
0.35.1 (b55f555)

$ tmux -V
tmux next-3.4

$ echo "foo\nbar\nbaz" | fzf-tmux -p

[damnskippy]

This issue is resolved after building tmux from the latest sources.