I'm struggling to find a proper "Doom II: Hell on Earth" wad.
I got my version of Doom 2 on Epic Games Store. When using its doom2.wad:
DSDA Doom says in console: "Playing: DOOM 2: Hell on Earth (BFG Edition)"
Demos for UV Max + reality on maps 6 & 32 desync
So I found a different doom2.wad on the internet. When using it:
DSDA Doom says in console: "Playing: DOOM 2: Hell on Earth"
Demos for UV Max + reality on maps 6 & 32 do not desync
However, now demos on map 2 desync
In this version of map 2, the left switch at the begining has bars in front of it, similar to red bars in front of the right switch. These bars require a player to interact with them in order for them to lower. Since these bars obviously don't exist in a proper version, demos desync when approaching the switch.
BFG version of map 6 looks absolutely identical to a non BFG version. But for some reason demos desync after taking an elevator back to the first room after picking the blue key and activating the crusher.
Maps 31 & 32 in BFG version have all SS soldiers replaced with zombiemen. Map 32 desyncs after picking the invulnerability sphere.