Ubuntu 18.04 client works intermittently. Chat stop syncing on desktop client after a few minutes

After launching the client, it works for several minutes and then stops syncing chat. Takes up to 10min after sending a chat message for it to sync to the other user (most of the time chat message fails but not every time). If I use my phone client messages get through to the other user with no problem.
I tried uninstalling and re-installing the client several times, and the same issue occurs. I tried installing a nightly release (which im currently on), and client does the same.
Keybase GUI Version: 4.5.0-20190830160059+530598f59c

Start by reproducing the chat-sync failure on Ubuntu 18.04 with Keybase GUI version 4.5.0-20190830160059+530598f59, noting the difference between desktop and phone clients. Trace the desktop client's sync behavior after several minutes; done means messages reliably reach the other user without long delays or intermittent failures.

Written by the indexing model from the issue text.