Google is working on a fix for their router data count bug, as they have reportedly acknowledged that they're aware of the problem with their OnHub router and Google Wifi mesh networks where the app is miscounting data usage. Though they have apparently mentioned that a fix is currently being worked on they haven't stated how long it would take before the fix is actually implemented, meaning it could be a little while before users see an update roll out to either of these Wi-Fi router products that Google sells. The silver lining, though, is that the fix is coming.
For Google to acknowledge the problem and issue a fix for it, it's quite likely that the issue is widespread enough that it's affecting a pretty good sized number of users who have either the OnHub router or a Google Wifi setup in their homes. According to the details, the Google Wifi application is displaying usage stats that seem off and are well over the amount that's actually being recorded by internet service providers. While this might not necessarily be a huge issue in terms of how the internet in your home might actually work, it could be a little bit annoying if you're usually keen on keeping track of how much data you're using for whatever reason.
Google notes that they will be reaching out to users who have had the problem and will be doing so via email once they have a fix ready and will be sending it out to users, so users who have an OnHub router or Google Wifi configured in their home will want to keep an eye on their email for the notification that the fix is good to go. Since both Wi-Fi systems are also controlled by an app, and updates come through those devices over the web, chances are that a notification will come through alerting users to an update around the same time or even before Google's emails go out, so users could simply keep an eye on their Google Wifi app as well and continually check to see if there are any updates available from time to time.