According to the official article this is intentional.
"Some are hidden underground, under the sea, or buried in sand"
https://www.minecraft.net/en-us/article/minecraft-snapshot-20w16a
First thing to make sure is to use the same version. Also 1.15.2 can't join 1.15.1.
This isn't a bug. This was changed years ago. You no longer use 30 levels to enchant.
I just like to use my own settings for hotkeys as it is more comfortable for me.
And yes, I am pressing both of them and this is really unnerving to activate it every time I sprint and use the hotkey.
I'd suggest adding more information as there can't be anything done without.
Without information it will surely get marked as invalid.
This was reported a few times already. I don't know to mark it as duplicate otherwise I'd do it.
When I tried to use /locate on the new structures it worked fine but it teleported me around 50+ blocks away from the structure. I suggest you try to find it in spectator mode.
Reproduced it, it really isn't fun to play like this.
Also, if you jump and hit a block in the air, you won't fall down normally it will 'bug'/lag you down.
Can be described as the same motion when starting to fly with an elytra although you down wear one.
I tried to reproduce that but for me everything worked just fine.
Did you use a Snapshot?
Oh, didn't know this. Thanks.