i'm the same person that created the issue( https://bugs.mojang.com/browse/MC-143202 ).

in addition to the bug that has shown me infinity loading screen, i faced one more bug that suffered me. after killing an ender dragon, the end gateway portal that would suffer me was created and my inventory was fulled with items for reaching the ender city and getting elytra.

not to fall to the void to death after shooting ender pearl, i created water elevator and water gate that allowed me to pull myself into one block. then i pulled me into the end gateway portal, boom! i got spawned the starting platform! for a while, my brain started steaming that what the hack is going on. after my brain got that it was a new bug, i started to look for the one that was suffering the bug. there was some people that suffered the bug. and it seemd that i should create 11x11 full of non-transparet block(for spawning), so i made 11x11 blocks and when getting to the portal, boom! nothing has been improved! and after several times that i got into more times denying the bug wasn't gone, i give up solving the bug... i has lost my motivation to do minecraft since then. and for the last chance to give me the motivation that i can progress minecraft without bugs, i created an issue on here. though i don't expect that you guys will make improvements for the bug that i posted because i has seen that they aren't fixed for 1 year, but plz fix it if you can. please.

p.s i'll link my map file to the google drive

https://drive.google.com/drive/folders/1dFUOaSsjqkPrmnhr9_QuO6E7rCmC6_ze?usp=sharing