Lost session

if I remember correctly, I believe I previously experienced the same problem of losing session data when using the redirect() command in my code... but manage to side-step the issue at the time by using other ways to call the new page (without using the redirect() command directly).

I too am using out-ofbox settings and session data could be picked up in other php files of my app until I started to use a redirect() when I found all session data was lost in the redirected page.

I read about alternative redirect way to side-step issue and tried the header('Location...) solution but that also didn't work. I'm using PHP 7.4.5 and CI4.

Any advice welcome - thanks.