I have noticed the exact same problem that you mentioned in your post. I’m using an iPhone 8 Plus running iOS 13.4.1 and Rachio App version 4.1.4 with a Rachio 3 and Rachio wireless flow meter.
Hopefully @franz or @laura.bauman, or one of the Power Users can answer this or send it to the Rachio Techs for a possible fix. 
The same issue occurs on my iPad Pro as well. 
Do you have a Windows, Mac or Linux laptop or desktop? If so, does usage display improperly there? If so and you download the usage and open the .csv file, is the data there also bad?
Thank you for your reply.
As @welchgregusa mentioned is his post, when you first select the usage you get a Usage To Date screen which shows all zeros. If you select either the left or right arrow soft keys you get the correct usage from the previous month (left soft key) or the current month (right soft key).
I have a MacBook Pro and it shows the current month to date usage as soon as I open the site. It matches the current month usage reported in the Rachio app.
The concern is the initial zero Usage To Date screen on the iOS and iPadOS apps that require you to click to the previous or current month to see actually your data.
Here’s a screenshot from my iPhone today that shows the same Usage screen reporting zero usage that @welchgregusa first shared back on 5 April 2020.
@jestric We do have an issue with the controller not reporting zone data if the wireless flow meter is disconnected. If you reconnect it, or remove from your account the data should start reporting correctly. We are looking into the root cause of the issue. Thanks for your patience and have a great weekend!
Thank you for your reply. I appreciate the information concerning this issue.
I’ve never disconnected my wireless flow meter. For what it’s worth, I just removed it from my controller to see if that would correct the issue but regretfully it still shows zero usage to date even after restarting the app and the iPhone.
I’m heading outside to rescan the barcode and add the wireless flow meter back to my Rachio 3 to see if reconnecting it will help and get this functionality back.
I’ll let you know what happens.
Wireless flow meter added back to my Rachio 3 and recalibrated, but no change to the problem.
I hope that you and the entire Rachio Team have a great weekend as well. Stay safe! 
I had the engineering team review your account and it does look like there is reported usage. Does this look correct? Is there a different screen you are looking at? This is Android by the way.
Thanks!
The initial screen that is displayed says “Usage to date” but it is only populated with zeroes. I can get to this screen only after I touch the left or right direction soft keys which take me to the previous or current month.
Initial Screen:
Subsequent screen after touching the right direction soft key:
This should be resolved in the next release
Thank you for all of your hard work! From reading the posts on this forum I know that you’re a very busy individual. 
