Currently for 1.15.2 Forge

If you have a potion effect like Night Vision, the effects of Night Vision will disappear for a bit when you teleport to another dimension by a mod or you use the /execute command to enter a dimension. However, for potion effects that stay on the player somehow after dimension hopping, their icons will also disappear for a bit instead.

This is pretty annoying as if you are relying on something like Slow Falling or Blindness for something, this bug will make it not get applied to the player for several seconds after teleporting. Though oddly enough, this bug doesn't seem to happen with Nether Portals (despite the fact that this mod's logo has a Nether Portal lol. I couldn't think of another way to show this mod is about effects staying after dimension hopping)

Anyway, this small mod aims to apply workaround to keep the effects always on and the icon visible despite any teleportation method you use. Let me know if it causes issues or doesn't work as intended! :)

Here is an example of what I am talking about.

Top is the vanilla bug itself and the bottom is when using this mod to fix the bug.

And here's another example of the bug impacting not just Night Vision but also Slow Falling and Blindness.

SyncPotionEffects (Forge)