Pretty sure most of you already know this but for those who don’t: you have two clipboards in Linux. One is the traditional clipboard where you copy with control c and paste with control v. The other one is when you highlight text and use the mouse middle click to paste text.
More details here.
For copying from Tmux, I recommend tmux-yank. There are also multiple plugins allowing you to copy predefined set of text types (IP adresses, URLs, etc…). I’m currently using tmux-thumbs. Note that you have to set custom command in tmux-thums to actually copy the text to xclip or whatever you are using. example in my dotfiles