The need to eat more doesn't surprise me whatsoever, just look at the boost in energy requirements by training. Also it shouldn't surprise you given what I said and what you know about serious athletic training (cough cough, Phelps's 13,000 calorie days). In any case, varying your training is in MOST cases best for overall size AND overall leanness. If you're a competitive bodybuilder, no. But if you want to be lean and jacked, most probably yes.
The reason is very basic and exactly what I said above: your body can adapt to any one tool you use (weights, cardio, sprints, weighted conditioning, etc). It can adapt to any one requirement. Weights is the hardest to adapt to, and in some sense as far as strength goes you never really ADAPT to it, but in terms of metabolic demands and leanness it does adapt because the more you practice something the more efficient you get at it...and the more efficient you get the less calories you use for the exact same task. You start running, you suck wind after 5 minutes and everything hurts after 30 minutes, but 6 weeks later you run for 30 minutes and feel ok. That's great for running, not great for fat loss--it means your body figured out how to become efficient and burn less calories to achieve the same result as the first time you did it.
The goal of getting lean is to be as IN-efficient as possible in calorie use: preventing metabolic adaptation. This is a different subject entirely from adapting to a weight load to force muscle to gain strength or size, so don't think about it that way.
Since you don't want to adapt, use more than 1 tool at a time: the body has a much harder time adapting to a mix of methods than it does any one method (side note: this is why even coaches who dislike steady state cardio for fat loss will use some in a program in addition to HIIT and weights).
Ok, so you say you want mostly to gain muscle right now, but you are under a small misunderstanding: to gain appreciable muscle you need a calorie excess. No ifs and or buts. To recomp your body fat SLOWLY you can play with that a bit and sort of eat a maintenance level of calories, focus on getting stronger and over time you'll get leaner especially if you use multiple tools in your training toolbox. But if you want significant muscle you need a calorie surplus. This also means you will not lose fat. You can gain slowly and gain less fat than a dirty bulk, stay fairly close in body fat to where you started...but you still won't get leaner.
There is a bit of an exception when one goes from only using 1 single training tool (weightlifting) to using multiple methods for the first time, because of the demand on the body's resources, but I tell people not to count on it. So you need to decide what your biggest single goal is and then accept the other consequences of pursuing that one primary goal.
I still think you should change your split, I just want you to be aware.
Training-wise: If you are doing fasted cardio and then pretty much immediately going to the gym for a strength workout (within 30 minutes) then you need more than just a banana and 2 TB peanut butter. At the very least I would have carbs and protein with me DURING my weight sessions as well as before. At least another banana and a scoop of protein powder.
It's not a problem to only do 20 minutes of fasted cardio 3x a week (assuming it's easy steady state cardio rather than hard/demanding steady running or biking). I would fuel your workouts better though.
I would take at least 1 off day, and would rather you take 2 off days from all training--if you do end up changing your workout split you definitely do not want to push that to 7 days a week in the gym. There's a reason theres only 4-5 days of weights in there. Obviously walks or bike rides around trails or the neighborhood aren't counted, but it is more demanding.
Diet wise: Eat for your goals. Seriously. It sounds trite but it is the best way to do it. Are you always hungry now? Do you feel adequate energy for your training (in general, bad days happen of course)? If so then I would make small changes but I wouldn't do crazy things abruptly. Generally speaking small modifications are easier to tolerate physically. Adding 600 calories in one fell swoop is a bad idea.
In general if you feel always hungry, I would add calories. If you feel pretty even most times then I would not add a ton of calories until your new split happens and your body spools up. I think your protein is good, or even a bit higher than necessary. I won't say 'too high' because I think protein is fine, but if looking to lose fat as a primary thing there comes a point of too much, because your body can convert it to glucose. I think that's not the big worry for you, but it is possible and it has happened to people that I took on as clients.
I like carb cycling and I like moderate carbs. You don't have a bad diet, it would mostly be adjustments to nutrient timing. I would suggest you put the most carbs around your biggest activity times of the day--pre-training/post training, and during the first half of the work day. I think you can add carbs but I would do so carefully (small additions). I would take the most carbs on your hardest training days and the least carbs on your easiest training days. For fat you can do whatever, but in the interests of feeling 'full' I don't like to go too low personally. In any case you need some amount of fat to run your immune system, joints, etc., so I would never go lower than about 30% of your lean bodyweight for long periods of time.
Gauge the swapping out of fat for muscle by your belly button measurement and any other measurements you might have like bicep or legs combined with strength levels or scale. That's the way to tell.
I might suggest Carbolin 19 for help with muscle and fat loss, and TUDCA for insulin sensitivity at ~750mg - 1000mg a day (get the powder, its way more cost effective at that dose) It's known as a liver supplement but it has demonstrated remarkable ability at improving muscle insulin sensitivity, which is great for both fat loss and gaining lean mass.