Syncing broken on some accounts

[catfromplan9]

Syncing is broken on accounts with a significant amount of data relating to them. The sync never completes. It may take 30 seconds for my client to do a v3 sync on that account, but matrix-nio will get stuck indefinitely. Using a different account resolves the issue, but I would rather not make a new bot account every time my bot becomes used in too many rooms and the syncing breaks