All forwarded mail going to junk

I didn't change any settings, but now all forwarded mail from another account goes straight to junk. I "not junk"ed everything line by line, but new business e mails come in and continue to go there. How can I stop this? I looked at my list of blocked senders, and none of the e mails going to junk are blocked.

Are there any consistent qualities to the email that you could use to build a filter?

Are they always from the same sender? Anything consistent in the subject line?

What kind of account is forwarding the mail? Where is it being received?

to Email Questions!

No, there is no consistency. I keep unjunking the same senders, which are mostly forwards from my business account. I've gone into safe sender list to list that account as safe, to no avail. I dont know how to build a filter. I just want it to go back to how it was.