Block outline is flickering. I use Lunar Client on 1.16.5, The built-in block outline flickers. The default outline still, does just a lot less noticeably. The texture pack seems to not affect
X-Ray Texture Pack (1.20, 1.19) for MCPE/Bedrock with Outline - 9Minecraft.Net
MCPE/Bedrock White Block Outline (with 1.16.200 Support) – .mcpack – MCBedrock Forum