It is still noticeable that some strokes disappear. It might be related to the new sync flag/actions sync, but probably not. Happening consistently. Looks like replaced by the snapshot? Restoration broken?

I think this happens when the player is continuing the stroke, and performHistorySyncClient is called. I've noticed Duplicating action! messages when this happens. Looks like commit it either not set in time or ignored when stroke continues. Maybe multi-threading issue?

Should be more or less fixed in 0.21.1, waiting for reports