Question about EMA performance

So i use 5 and 8 ema on 4h chart, but my question is, does the ema performace ever really change? Like when they crossover price moves, do ema crossovers ever really change?

Ema’s are just averages of price. So as price changes, the ema changes. The ema laggs because it is an average of the price over a fixed time period. It smoothens out spikes.