Fans are powered by CC Bec Pro (the unit beside the RX).

No it's not fans overload.
I am running at the highest settings and highest pinion.
But still not fast enough for me, so I will run 6s lipo with 2650KV.
I've also 2200KV, but I am keeping as spare.

Hmmm anyone knows where I can buy pionion above 23T.