junk mail with microsoft products

Hi, Emails always end up in junk folder with @hotmail.com, @outlook.com etc and office365 servers. All domains on our servers are authenticated with SPF/DKIM . Whenever I have an issue with this, I do a test with @hotmail.com, check the header and everything is fine. DKIM pass, SPF pass. The email is never blocked but always end up in SPAM. I don't see any logic with microsoft products. On the contrary, with gmail, they always end up in the inbox (unless something like SPF doesn't match, RDNS etc). I've tried to contact @hotmail.com, but their awnser is not really helpful (like a bot). I feel like it's only related to the IP reputation but again can't find anything that would indicate so. If it's a new IP or had an issue with it, it goes in SPAM folder for weeks and even months. For more than 100 IPs, I have like 5 IPs that are working properly with @hotmail.com even thought some bad IP should be working (SPF,DKIM, emails monitored, no SPAM, good reputation on cisco, barracuda etc). Anyone have this problem ? For the moment, the only thing I do is relay the emails being sent to @hotmail.com, @outlook.com to a different SMTP with a that works with @hotmail.com. When it stop working, I change the relay to another IP etc. So it's only a work around. Thank you