I have a relatively small sales model that I resue with about 100 different external customers of ours. Each time I set a new customer up, I save that report in their name, and share that new report. If the report content was the exact same, I'd just use RLS... My point is that I have years of this setup process to compare to.
Prior to a few months ago, I'd open the last report created, filter for the new customer number in Power Query, then let the sales table do its merge thing and isolate just that customer sales. Load the model, good to go. What was a five minute process, is now a half hour process just to refresh all the tables in PowerQuery, and eventually get to my changes in customer name. I'd love to learn about reasons that would cause this, and ways to prevent it. I had thought it may be a limitation of the machine, however I also now experience this on a different machine and Power BI account.
Accessing on premisis data sources (Excel/CSV), and working with 3M in sales records and 15K Customer records.