Cannot push to git repo (BServer: block does not exist), and get lots of "Unknown RPC errors" in the app

I can no longer seem to do very much in the app. I can login, but most actions give me an "Unknown rpc error".

It's possibly a red herring, but I have done two, (admittedly slightly strange) things since signing up:

• Added my phone as a device, then revoked it, and re-added it with a different name
• Created a git repo, pushed to it successfully, then deleted it and created a new one (with the same name but lowercased).

If I try and do any git actions on the repo that is listed in keybase, I get:

Initializing Keybase... done.
Syncing with Keybase... BServer: block does not exist
git-remote-keybase error: (1) BServer: block does not exist

If I try and create repos in the app, I get "Unknown RPC Error"

If I try and create a repo from the command line I get:

❯ keybase git create hello-world
libkb.AppStatusError{Code:2704, Name:"BLOCK_NONEXISTENT", Desc:"", Fields:map[string]string{}}
▶ ERROR  (code 2704)

my log id: 843483fcfb6658c3bd47971c

The report names the Keybase app, the keybase git create command, and git-remote-keybase, and includes log id 843483fcfb6658c3bd47971c. Start by reproducing the BLOCK_NONEXISTENT and Unknown RPC errors using those entry points; done means git actions and repository creation no longer fail with these errors.