By using luma and fbi will make eshop and online game useless
If the console is banned, online and sometimes the eShop will not work.
CFW does not result in a ban but running homebrew CIAs has within the last few years has resulted in bans so all homebrew should be run via homebrew launcher using rosalina.
if you cannot use eShop, the 3DS you have is banned or a new 3DS that was incorrectly region changed.