Has this issue started again in the latest Edge update 150.0.4078.48. Before this version, a .jnlp file would open automatically from Edge or a downloaded excel file would open if you clicked on Open File to open it.
Now you must specifically Open the Downloads folder to open the file (applicable to .jnlp and .xls and .msg file types). Prior to this update, all was working OK in this respect since 149.0.4022.62