New refresh error on large model

We have a very large import model (24GB) which has intermittently failed to refresh due to throttling/memory issues. After some improvements made last week, we've had no failures until this morning. This morning we had a brand new error, and I can't seem to find any results for it on Google that are related to Power BI:

Data source error: Invalid attempt to call CheckDataIsReady when reader is closed.. The exception was raised by the IDataReader interface. Please review the error message and provider documentation for further information and corrective action.

This error occurred once after 25 minutes, followed by another error (Data source error: ExecuteReader requires an open and available Connection. The connection's current state is closed.. The exception was raised by the IDbCommand interface.) after a few seconds, and then the same new error occurred twice more after 23 and 46 minutes:

I did kick off another refresh which completed in 1.5 hours, which is typical for this model, so now I'm just wondering if others have had this issue and if so, how to avoid it in the future.

Some more info:

• We have several other data models using the same source (Azure Synapse Analytics) which refreshed around the same time with no issues, including one that ran for 35 minutes without throwing this error.
• This data model originated as a tabular model so is not a typical Power BI model, but so is the one that completed after 35 minutes.
• Our data models are on a Fabric F256 Capacity.