The Onions, Carrots and Apple kind of stand out as possible contributors, depending on quantities I guess.

Have you tried the idea that some other people have suggested - upping your fats and reducing protein ? Or the reverse. It seems the idea is to change whatever it is you are doing now and see if it gets results.

Also, if you are not currently tracking those food items in some kind of program (My Fitness Pal online is excellent and free), then you really don't know where you are in terms of total macros (fat, protein, carbs) and your total calorie intake.
You need that information first and then you can tweak the quantities - wait a couple of weeks, see what happens and maybe try a different strategy.

That said - I am also in the turtle club (turned 60 this fall) - and after 4 months of LCHF I have literally had only a few pounds weight difference via the scale but the measuring tape is proving I am having slow but steady progress. I am going to assume it is lean tissue building and stay positive.

I can actually feel the difference too, the fat seems different and I feel leaner even if my outward appearance hasn't drastically changed yet.

4 months isn't long enough to decide if this method is truly working, and it really doesn't matter as I am not going back to carb eating no matter what happens. It cured my IBS in one week, I have lots of energy, and I rarely get hungry between meals. I can also frequently go for 12-16 hours between meals with no suffering so that is kind of a bonus effect too.

FYI - This is another stall breaker method used by some - IF - or intermittent fasting. This is where every other day or two you go for an extended time without eating (coffee, liquids only) and then only eat meals during a shortened span of hours like 6-8 and then fast again. Some people do this quite often, some do it once a week but apparently it is enough to trigger weight loss when they are stalled.