PineScript proper way of comparing previous indicator data?

I'm trying to do an indicator on pinescript and I'm pretty much new to the language. This is the code:

study("Tester", overlay = true)

ma = ema(close, 50)

signal = (high[1] > ma[1] and close[1] < ma[1])? true : false

plotshape(signal, location = location.abovebar, style = shape.xcross)

And my expected result is an x every time the upper wick of a candle goes above the 50 period ema but closes below it. I'm getting Xs where I can't seem to find any reason on why the condition triggers.

EDIT

Code adjusted to non-shifted bar:

study("Tester", overlay = true)

ma = ema(close, 50)

signal = (high > ma and close < ma)? true : false

plotshape(signal, location = location.abovebar, style = shape.xcross)

Image of the issue:

Thats because you shift your signal by 1 bar, so the signal X is printed on the candle when the condition was met on the previous bar.

if you want to plot X exactly on the candle where the condition was met - don't use history reference operator ([1]).

study("Tester", overlay = true)
ma = ema(close, 50)
plot(ma)
signal = (high > ma and close < ma)? true : false
plotshape(signal, location = location.abovebar, style = shape.xcross)