I use a 5/0 Zoom Horny Toad single hook with all my frogs and sometimes go weightless and sometimes I add some weight for longer casts...
I do not like double hooks on toads but I know plenty of people do. My guess it has something to do with the hookset? I use the BPS Humpin Toad alot because it has a hook slot on top for easy texposing, and if I use the Stanley Ribbits, I think I use a 4/0 for smaller ones, and I use 5/0 I think, I rarely go bigger than that..I use heavy line, rod, and I let the fish take it and then I swing Hard since casts are usually far....
One Trick that helps me is I keep my rod high around 10 oclock, and as I am reeling, once I get a strike, I lower the rod and I turn toward the fish or lean forward before setting the hook. If you are driving home 2 thick hooks you need to swing hard, especially if making long casts, and same with using a single hook since if you have 50lb braid and a thin guage hook it bends, Make sure the rod is strong enough back bone wise and try to give them extra time and give a 2 count before swinging and make sure you feel the weight of the fish, and then swing hard and do not let slack get into the line which often can happen after swinging since the momentum causes fish to swim at you really fast..That is why a fast reel makes frog fishing easier, I used to lose 70% of Hollow body frog fish because they would get off half way to the boat until I focused on tension and power....
Hope that helps...You Tube has some great videos that show guys catching bass on toads and frogs, and that should help you figure out the mistake..I still make tons of mistakes when fishing Swimbaits that are not on top so I can't see and when texas riggged weedless, I often pull the bait away from the fish before getting a good set...
Keep in mind..Some days fish will simply slap at your frog to either stun it and come back, or they just strike it without the intent to kill it...That is just the way it is sometimes, and some days they spit it out faster than you can react...
FYI...It sounds like you are fishing the bait the right way...I know you said Ribbit but are you maybe using the Hollow Ribbits that come in a 2 pack with the 6/0 double hook? Top Toad I think it is called but I know it says Ribbit on the packs I think....
If that is the case, I have heard mixed reviews from people who know what they are doing, some say terrible, some say awesome, I just have never used them yet. I only thought of this when you listed the colors, since I never see a bluegill colored Ribbit in the stores but I am sure they make one...I consider the Ribbit the regular soft toad...