Email not forwarded after "mark as non-spam"

Email not forwarded after "mark as non-spam"

Hi,

I have email forwarding set up and it's working fine.
Some of the mail that end up in spam are not spam, so I mark them as non-spam.
Those mails, however, are not being forwarded after marking them as non-spam. Why?

I found this old topic that mentions that forwarding should happen:
https://help.zoho.com/portal/community/topic/spam-forwarding

Any help is appreciated.
Thanks.