Error in composite models with Direct Query to Power BI datasets

Hello,

When attempting to refresh existing or create new composite models with a Direct Query connection to Power BI datasets, we're seing the errors below:

The models where we first encountered this error were created two weeks ago and had been refreshing without issue until we went to change one of the connection strings yesterday afternoon and noticed the error. My team and others in our organization have built many composite models over the past several months without seeing this issue. We're seeing this same error across multiple models, and nothing has changed with any of these models in several weeks as we are currently in a code freeze.

Of note, this error only occurs when we bring the model's Metrics table into the composite model, as this is where the auto-generated folder containing the FormatString measures are stored. However, we can only choose to bring the entire Metrics table into the model or leave it out entirely -  we do not have the option of omitting only that folder. Additionally, virtually every composite model within the organization requires the inclusion of the Metrics table.

We've also determined that when we take an existing model, save to a new workspace, remove the calculation groups, and then attempt to create a new composite model we don't see this error. Removing the calculation groups from our existing models is not an option for us, but it does make us feel as though this issue is related to calculation groups in some way.

Our working assumption is that this is related in some way to a product update, given that it began happening suddenly without any changes on our end. This is a pretty urgent issue, so any guidance would be greatly appreciated!