I am phasing into solid blocks in my singleplayer world, when i log out of the world and back in i am not able to phase into blocks anymore, but after some time its glitching again. It seems sort of random when it starts doing that. The blocks do suffocation damage. So far it happened with

• closed fence gates
• beehives
• crimson stems
• observers,

but i think it can happen with most other blocks.