Is it just me or...?

I've encountered several series so far in my ranked league career. I'm a support main that started in season 3 at Silver 5. To this day I'm still in silver. Silver 2 currently to be precise.

It seems to me that every time I'm in a series I either get extremely trollish teammates or just get worse ones while getting matched against extremely competent teams.

Just recently I went on a 6 game win streak with Nami and everything was smooth sailing. I had awesome teammates, zero toxicity, jolly co-operation!

And then it happened... I entered the first lobby of my series and from then on it was a toxic shit storm of badness.

Has anyone seen a post from a Rioter confirming or denying this suspicion? Do we truly get all the toxic and bads in series on purpose?