i had a a Problem with lag and low fps before but also i had some problems with slow loading for chunks

in 1.16 i did't had any issue with lag or slow loading for chunks/world 

but after i create a new world evrything was normal 

untile i log out and then log in agian i was in the game but no chunks are loaded so it seems like i was in the void

to confirm i tried to play in old version (1.16.5) i created new world and log out and log in i had no such problems / also no lag no low fps 

 some notes:

• like i siad i did't had any problems when i was on 1.16 so the problems is from 1.17 chunks loading

• i did't use any mods or datapacks or add-on
• the screenshots are from a survival world 
• i triad to test if it's happen on a creative world but the problem is the same ( slow loading chunk and spawned in the void )
• i test the same thing in 1.16.5 and i had no problem playing chunks where loading normaly fps was high no lag
• also there is something i did't talk about which is the loading screen (in the screenshots) it was kinda slow , in 1.16 if you log out and in agian it will be faster