I contacted the support at the twentytwenty theme. They asked me to request that you open a ticket if you think the issue is with their theme.
Here is their response:
I’m not able to replicate the scenario from the screenshot you showed in the original report, but it looks to me like bbPress’ themes and styles are being removed from the page for some reason. As @desrosj mentioned though, the plugin you are working with is a premium one, so it’s not possible for us to look into this any deeper, but it certainly appears to be a problem on their end. If they know for certain the problem is with the theme, I would suggest you let them know that they should open a ticket (or provide details in this one) as to what that problem is, so we can find a solution together.