The explanation is plausible, but like I said, Sync has a workaround built in to account for that situation. Is more than 2 minutes passing between the creation of the note and the syncing/replacement of the old version? If so, that’s expected and we can explore why it’s taking so long. If not, that’s surprising and may call for a bug report.
Either way, try the troubleshooting steps in the Obsidian debugging guide to rule out various potential causes.