Neo-tree looking weird

So I'm following the guide of typecraft on youtube on setting up neovim. however i encountered several issues (mostly ui / cosmetics, but still it triggers me). In his setup the neo-tree has a clean look, with the selected file being highlighted (see attached screenshot).

typecraft's neo-tree

However on my setup it has sort of an underline. Also what's going on with all the tildes (~)
Aswell when looking at the "add-file" interface mine just looks weird (happens regardless of the colorscheme)

https://preview.redd.it/s8xzm7fx2ivc1.png?width=3456&format=png&auto=webp&s=b529852c8861ed05a11cece7625772b7f7df9cd8

and mine has this pink border i can't explain where it's from

https://preview.redd.it/xgmclpko2ivc1.png?width=3454&format=png&auto=webp&s=7a4e2e10789ffb092a025f9f491c04134bade40b

To my setup:
Mac Book air M2 running sonoma 14.0
terminal: iTerm2 build 3.4.23 with JetBrainsMonoNL Nerd Font
shell: zsh with oh-my-zsh and powerline10k
nvim and all plugins freshly installed today

the neotree config:

https://preview.redd.it/prwvpi7r2ivc1.png?width=3456&format=png&auto=webp&s=cf9ae4ee96c68ca67be27b704b117342ef57850d

Can somebody explain to me whats going on / what more information you guys might need. I'm trying to learn and understand all of the nvim / plugin configs etc.

Thanks in advance