I took a course from a local conflict mediation charity based around the Harvard Negotiation Project's framework on Difficult Conversations (So another vote for soft skills, really). It completely changed the way I think about dealing with internal & client side comms - with a big part of the focus being on trying to understand the underlying motivations behind people you're communicating with. Honestly, this feeds into how I try to communicate with people in a non-work context too, so, can't recommend it highly enough.
Not sure how helpful that'll be in terms of finding a course that you can access yourself, but link to the original book outlining the framework below.
https://www.pon.harvard.edu/shop/difficult-conversations-how...