.NET Core 3.1 builds are failing

the Travis builds for our .NET Core 3.1 projects are failing. I can’t provide a link to one of the failed builds as it’s under our organization. Here’s a relevant snippet of the .travis.yml file:

language: csharp
os: linux
dist: xenial
mono: none
dotnet: 3.1

and the build log’s output:

Please advise @Joshua-Anderson. Thanks!

When reporting problems, please include relevant build URLs. Thanks.