Leading edge or trailing edge stall?
The Benedek 10355 clearly stalls with separation starting from the trailing edge.
There is some discussion whether a laminar-to-turbulent transition due to rising pressure will always involve a laminar separation bubble, however short. But that bubble does not constitute a leading edge stall.
XFOIL is not meant for flow simulation deep into the stall region. It does amazingly well to capture the initial stall but cannot possibly model the extended separated flow well into the stall accurately. I am actually surprised that it still produces converging results at such high angles of attack.
In short, I would not expect the XFOIL results above 12° AoA to model accurately what is happening in reality. Especially that sharp drop in lift at around 21° looks very much like the code settling on another solution but not something that can be expected in real life.