The bug
When flying off of soul sand or soul soil with creative mode or elytra, your soul speed "effect" stays and keeps the FOV until you land, resulting in an FOV shift. Same also happens when getting affected with levitation. One way to fix this incredibly annoying bug is to disable the soul speed "effect" when flying in creative mode, using an elytra, or levitating.
To reproduce
Be in Creative mode
Equip soul speed boots
Stand on top of soul sand or soul soil
→ Notice that your FOV increasesFly up into the air
→ ❌ The FOV doesn't decrease again
Linked issues
is duplicated by
relates to
Attachments
Comments

Can still be reproduced in 1.16 Pre-release 1 with the Levitation effect. However, it can no longer be reproduced when flying in Creative mode or using an Elytra.
Although it can be reproduced with Levitation, it would be pointless since the player is not able to walk on soul blocks. Therefore, it is fixed.