When summoning the Wither Boss in the current 1.16.0.55 Beta, the Wither begins to move and attack while it is still white and generating its health bar instead of staying in place before the bar fills up. After it reaches full health and the white appearance fades the Wither Boss' heads are backwards and don't properly look in the direction they fire Wither Skull projectiles.
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We're actually already tracking these issues at MCPE-64537 and MCPE-48265, so I will resolve and link this ticket as a duplicate.
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