Affects only people who use datapacks using dimension-type of the end while effects is targeting minecraft:the_end. 

Steps to reproduce:

1. Add datapack with the following set:

{
  "ambient_light": 0,
  "bed_works": false,
  "coordinate_scale": 1,
  "effects": "minecraft:the_end",
  "has_ceiling": false,
  "has_raids": true,
  "has_skylight": true,
  "height": 384,
  "infiniburn": "#minecraft:infiniburn_end",
  "logical_height": 384,
  "min_y": 0,
  "monster_spawn_block_light_limit": 0,
  "monster_spawn_light_level": {
    "type": "minecraft:uniform",
    "value": {
      "max_inclusive": 7,
      "min_inclusive": 0
    }
  },
  "natural": false,
  "piglin_safe": false,
  "respawn_anchor_works": true,
  "ultrawarm": false
{color:#d4d4d4}}
2. Restart server

3. Go to the end, place respawn anchor, and right click on it to set spawn point

4. go to the end portal and try to leave the end – it'll teleport you back to respawn anchor