Confirm. All of my item frames are gone! Until the next snapshot, I'll have to go back to using chests to store my maps.
Even on auto-jump, two slopes in a row will result in your character moving into the block. You can't autojump unless you are relatively far from the block.
I think this is a consequence of the changed collision mechanics as mentioned in the update.
And adding to the variety of machines experiencing this: Debian Testing on OpenJDK 11.0.2+7deb1 64-bit.
I really hope this bug is fixed in the next snapshot, but it's the day before the snapshot and the bug is still unassigned, so it doesn't seem like it...