The title, subtitle, and sometimes the action bar renders in front of the narrator's text. The action bar text will only overlap on underlined or strikethrough areas. The text is still tinted by the narrator box but renders in front making it difficult or impossible to read the subtitle texts. This relates to MC-173672 and MC-187267.

To replicate:

1. Go to Game Menu>Options>Accesibility Settings and turn on Narrator if it isn't already
2. Recommended (not required) turn off speaker
3. In Game Menu>Options>Music&Sounds... ensure Ambient/Environment is on (used in commands)
4. In order to consistently get enough sounds put the following commands in repeating command blocks that are on:
   /playsound minecraft:entity.slime.death ambient @p
   /playsound minecraft:entity.stray.death ambient @p
   /playsound minecraft:entity.skeleton.death ambient @p
   /playsound minecraft:entity.chicken.death ambient @p
   /playsound minecraft:entity.parrot.death ambient @p
   /playsound minecraft:entity.pig.death ambient @p
   /playsound minecraft:entity.sheep.death ambient @p
   /playsound minecraft:entity.cow.death ambient @p
   /playsound minecraft:entity.turtle.death ambient @p
   /playsound minecraft:entity.fox.death ambient @p
   /playsound minecraft:entity.polar_bear.death ambient @p
   /playsound minecraft:entity.panda.death ambient @p
   /playsound minecraft:entity.wolf.death ambient @p
   /playsound minecraft:entity.cat.death ambient @p
   /playsound minecraft:entity.ocelot.death ambient @p
   /playsound minecraft:entity.bee.death ambient @p
   /playsound minecraft:entity.magma_cube.death ambient @p
   /playsound minecraft:entity.ender_dragon.death ambient @p
   /playsound minecraft:entity.enderman.death ambient @p
   /playsound minecraft:entity.creeper.death ambient @p
   /playsound minecraft:entity.spider.death ambient @p
   /playsound minecraft:entity.zombified_piglin.death ambient @p
   /playsound minecraft:entity.husk.death ambient @p
   /playsound minecraft:entity.zombie.death ambient @p
5. Make sure screen is full
6. Run these commands and observe the rendering issues

Title:
/title @a title ["",

{"text":"ABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZ","bold":true,"underlined":true,"strikethrough":true}

]

Subtitle (Requires active title):
/title @a subtitle ["",

{"text":"ABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZ","bold":true,"underlined":true,"strikethrough":true}

]
Actionbar (Only on strikethrough/underline not text):
/title @a actionbar ["",

{"text":"ABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZABCDEFGHIJKLMNOPQRSTUVXYZ","bold":true,"underlined":true,"strikethrough":true}

]