There is a pattern of retries built into the code, but syncing has no ability to repair failures, and there have been hand-documented cases where even with retries, there is significant data loss: https://github.com/LemmyNet/lemmy/issues/3101
I am starting to see some partial page loads, broken pages - bug with actual data content of posting/comments on them. I expect other federation servers are swarming to the site to try and replicate - and it's causing a mess given how many communities lemmy.ml is center of.