first i'll have the video of the bug here to show what is exactly happening https://youtu.be/r_nzSPzvU28 . As you see i cannot get out of the bed, at first I thought it might of been mod related, so i hopped into a singleplayer world without any mods and tried to recreate the issue and it happened once every 5-10 times when sleeping. All of what causes it exactly, i don't know but it is a random bug as it has no set time of when it happens.