When using the PowerApps visual in PowerBI, I sometimes need to add more fields to the app. When I add new fields to the existing PowerApp visual, I cannot see those fields in the PowerApps studio, even after saving - closing - and reopening the PowerApp in the studio.
The only solution I have found is to remake the PowerApp visual by way of deleting the existing visual, creating a new visual with the (many, many) fields I'm passing, and then assigning it to my PowerApp. This is a very cumbersome process, and I would assume that there is a more efficient way to do this.
How do you edit the embedded app in your Power BI Report? Using PowerApps Studio for web directly or Edit the embedded app from the Power BI report?
Based on the issue that you mentioned, I have made a test on my side, and don't have the issue that you mentioned.
If you made some fields changes associated with the PowerApps Custom Visual in your Power BI report, you must edit the app from within the Power BI service by selecting the ellipsis (...) and then selecting Edit. Otherwise, the changes won't be propagated to PowerApps, and the app will behave in unexpected ways.
In other words, you must edit the embedded app from within your Power BI report, rather than edit the app individually using PowerApps Studio for web.
Please check the following GIF screenshot for more details:
Please also check the known limits with PowerApps Custom Visual in Power BI Report through the following article: