Would successive rejections of different papers by the same journal lower the probability of acceptance of the next submission to the same journal?
My guess about the situation is that your prior rejections will not significantly affect the editors' opinions on your new submission.

However, the fact of your prior repeated rejections is evidence that you are misjudging the suitability of your papers for that journal, either the aptness of the topic(s), or the level and quality. Thus, if I had to wager, I'd bet that you'll be rejected again... not because you were rejected before, but because the factors in play that led to your prior rejections will most likely manifest themselves in the present case.

So, really, you should get more-specific advice from an advisor or mentor about appropriate venue(s) for your papers, as well as possibly critiques of the writing style.