I tried this because I have the same issue as @FreshNeverFrozen.
However...
Changing the permissions (for the file itself as well as the folders) via chmod did not work - file is 'unwriteable'
Found this post in the UBports-Forum: https://forums.ubports.com/topic/9496/how-can-i-edit-file-in-etc-folder-on-ut-20-04-focal
...with the same result regarding the suggested procedure on https://ubports.com/en/blog/ubports-news-1/post/terminal-chapter-3-3073
(I did not try the Tweak tool install, though - not sure I would succeed given my level of understanding...)
So, to the