I have had the same issue since about 2am this morning - everything goes to the SPAM box despite using both the Outlook tools to mark as legit and the Avast antispam add in.
I've been searching on Outlook forums as I thought it was a Windows Defender issue (that also updated last night) but only found similar issues here in the Avast help.
Is there any fix yet? Everything I've tagged as safe - all new messages from these domains, individuals ends up in SPAM, and when you get 100s of emails a day, it's a good amount of time to move them so links/attachments can be seen.
I am on a 3-pc paid subscription to Avast. Avast Version same as last person to post. Version 7 0 1407