VMware said they could not reproduce this was Horizon Agent 7.7.0. I have a few pools upgraded from Horizon Agent 7.4.0 to 7.7.0 that I'll test with tomorrow. If you decide to open a SR I can provide ours so they can be linked.
What does the rest of your environment look like? Is this Internal or External? Is tunneling enabled (On the connection servers, security servers or UAG)? Are you using Blast or PCoIP?