Game freezes exiting portals both Nether and End

When exiting a nether or end portal the game freezes on creating terrain splash screen sometimes it will take a minute to load but world will not be rendered fully and has invisible walls where terrain render ends render distance is blank except for mobs,  I have to shutdown Minecraft and restart the program while in the portal upon restart game will load correctly and i exit portal this has been an issue since last update. I can no longer get a screen shot of the terrain render as now i have to close and reopen game whenever using the portal,