The good news, in v13.1, is that the bug for more than two plots seems to have been fixed.
The bad news is that I systematically get warnings for all uses of PlotLayout -> "Row" (or "Column") that look like "Part::partw: Part 2 of Charting`iHold[{-1.5 #1,-#2}] does not exist."
This is true for the example code in the StreamPlot help file, as well as the examples above.