Problem with fzf and tmux

[PasiY77]

I am working in remote linux servers and tmux is very important for me. But when I use tmux the fzf is not working always properly, lines and columns doesn't align and borders are missing than normally without tmux. Without tmux every thing is working fine.
One server I am using tmux 1.8 and fzf 0.30.
In other server it is working little better where I am using tmux 3.3 and fzf 0.30.
I can use this script from here: https://gist.github.com/junegunn/f4fca918e937e6bf5bad (carlfriedrich or maheshsundaram)
Then rounded edges are just straight lines and in first server sometimes lines and rows are not aligned (very difficult to read result).
ctrl+r is working if I don't use any own settings in .fzf.bash file.