This is my list of issues I have seen so far on my MacBook Pro (Retina, 13-inch, Mid 2014) with the Mojave beta:
1. Skype For Business Version 16.18.51 crashes a lot while just sitting open
2. In the Messages application the To: section that has people's names has dark text and is on the new themed dark background. Thus, it is very hard to read the people who you are sending the texts to.
3. Blutooth connections to my speakers do not work.