Bizarre - the site has javascript that disables selecting text on the article because "Content is protected".
Anyway, for 'copy protection' they are using wpcp_disable_selection https://myprogrammingnotes.com/protect-web-page-copied-using... , it hooks document.onselectstart and document.onmousedown. onselectstart is very abuse-able and has no place in User Agents just like the likes of onbeforeunload navigator.sendBeacon and window.opener, meaning you should probably hardcode disable it (userscript, or directly modding own browser). onmousedown is a bit more problematic and cant be dealt in automatic fashion. You will have to manually go to devtools every time and delete all onmousedown event listeners.