I have a problem with my 2.3.0 installation. Configurable product's price is not showing either on the catalog page or product page.
The second thing is this MSI. I may not fully understand it, but I think when a product is in stock in one of the three sources I set up, it should be "available" in the frontend.
Also, I have a problem with configurable product options not showing on product page, when one child product is set to "in stock", but with zero qty. This one worked with 2.2.6.