I don't know if anyone is still running into issues with the Edit Research Stock feature not sticking, but I've tested it fairly extensively and anytime I start building research quarters, or any building that increases science rating, the editor values entered won't stick and snap right back to what ever the default research stock was.
I've noticed that the "Edit Research Stock" feature works properly up until the Medieval era, then it does what everyone else has noted. I've managed to get throught he Ancient and Classical era pretty easily but then it doesn't work for Medieval onwards.
Minor irritation to be sure, but you can keep going regardless.