EDIT: Fixed, turns out tick speed was in the hundred thousands
Hello. I just updated my minecraft to 1.15 and hopped on a previous 1.14.4 world. It said all the stuff about backing up, or "i know what im doing." I backed up just in case and when i got in, it was laggy. Every 8 seconds or so, I would get a lag spike. In 1.14 i always had 114-130 fps. At some points, the lag would clear, but when i placed or destroyed a block, it had the block lag (where it would show up and then dissapear.) Also, when I spawned in some bees, they were there, but were frozen, buzzing, but not moving.
Also, I tried other worlds and it was fine...114 fps.
My specs are not great, but I have never had a problem with MC vanilla or modded.
-Windows 10 Home 64 BIt
-Intel Core i7-3610Qm CPU @ 2.30GHz (8 CPUs), ~2.3GHz
-NVIDIA GeForce GTX 670M
im not great with tech so yeah, if i didnt post something i needed to on the specs..sorry