I root-caused this to a change in jemalloc version. Prerelease 3 downgraded to LWJGL 3.1.6 (which includes jemalloc 5.1.0). Forcing the game to use lwjgl 3.2.1 (which includes jemalloc 5.2.0) solves the issue. See the details I wrote in MC-148505.
Sargun Vohra
I root-caused this to a change in jemalloc version. Prerelease 3 downgraded to LWJGL 3.1.6 (which includes jemalloc 5.1.0). Forcing the game to use lwjgl 3.2.1 (which includes jemalloc 5.2.0) solves the issue. See the details I wrote in MC-148505.