Entering a portal as you open a gui block (such as a chest) causes you to be unable to open GUIs.

If you enter a portal as you open a GUI block (such as a chest or an enderchest), it kicks you out sometimes and will usually keep the open animation and make it so that you are unable to open GUIs (other than your pause menu). Restarting Minecraft does resolve the issue.
Depicted near the end of this video: https://youtu.be/x3_BrNcH4SQ