Concatenate Labels Not Working in Service, but does work on Desktop

Hello!

I am having an issue where my published report does not function in the same way as my Desktop report. This is the visual giving me issues:

As you can see in this screenshot of the Desktop report, I am able to concatenate the x-axis and show the months within the year. However, when I publish this report online, the report looks different:

The concatenate labels option does not work on the website. I have seen several other posts suggesting that the sort is the issue, however I do not have an option to sort by x-axis as I am using a legend for my values:

Even with this being the case, I do not think my data or the way I built the visual should be an issue since the visual behaves correctly in the Desktop version. This seems to be a bug with the Service. Any way around this issue? We need to embed the report in a website, so I need the online version to be correct.