Yes.
Unfortunately we are encountering the errors are everywhere. We have installed UM on a brand new install with no plugins activated. When adding images to a brand new profile we were able to add a profile picture before the nonce error returned when attempting to upload a cover image. No cache ever used. Mutltisite install.
This nonce issue appears to be everywhere. We are set for launch but this is holding us back. We convinced the client to use UM over buddypress which is now proving problematic.
We had such amazing experiences in the past with UM we were a little shocked to run into issues.