They accept articles (and are lenient) to manuscripts that are from a lab whose PI has good relations with them.
How would you know? Do you have insider information as to how the journal makes decisions? Given you're a PhD student (and not an editorial board member or journal staff) I highly doubt you know how the journal is making decisions.
You write that your papers aren't even getting sent to peer review, and you think it's because you don't have good relations with the editors of the journal. If you truly think that, you are almost assuredly wrong. Good relations with the editors of a journal can positively bias them into accepting your papers, but poor relations will not bias them into rejection (and I say this based on years of experience in publishing).
Check out this question for another person theorizing about why their papers are getting desk rejected. Note the top-voted answer says nationality of the authors does not play a role in desk rejection, and it would be highly unethical if it did. The same also goes for identity.
As for how you can "push through" these desk rejections, also check out the question above, in particular xLeitx's answer. I quote:
Nationality of the authors does not directly play a role in either of these decisions. However, I would be lying if I did not say that desk rejects are significantly more common for middle or far eastern countries, such as Iran, Pakistan, or China. This is mostly because more authors in these countries submit papers that are blatantly outside of the scope of the journal, very poorly written, very poorly formatted (e.g., figures that are entirely unreadable), which do not follow at all the reporting conventions of the journal, or where there appears to be very close to no novelty in the work.
The bar to not getting desk rejected is usually fairly low (the best-of-the-best journals might have a higher bar). If you are not clearing it, odds are your presentation needs serious improvement, or the work is patently bad. Since you're a PhD student, you can attack both of these problems by asking your advisor. You can do this even if the work is unrelated to your thesis. Your advisor is there to help; it's up to you to approach them.