Seems as if the FPS & Physics are tied together, as when I get into the game after the character customisation, my jumps are fast, my movement speed is almost doubled compared to what it should be, and the cutscenes are desynced.

Any fixes? I'm on an AMD GPU and the High FPS Physics Fix mod that usually resolves this exact issue isn't working.
The mod is completely unplayable until this gets resolved.

Also am I the only person getting this issue? Because I cannot find a single other person having this same issue online.

Use AMD Chill to cap at 60FPS

Just bite the bullet and drop your refresh rate to 60hz. It's not that inconvenient and your experience will be much better overall. AMD Chill and frame limiter does NOT work correctly for this application. It's a variable average targeting your desired FPS, not a hard limit. The F4 game engine will speed up in many places as it's not a fixed rate. Also it just doesn't seem to be effective on Fallout in particular (try staring at a wall and zoom, 200fps again).

NVidia cards however use a different frame limiter and actually do work for this purpose. I've been replaying Fallout 3/NV and F4 with the profile set to 60fps when running at 120hz on a LG GSync OLED and a 4080 Super, and it's perfectly smooth; no speedups. My 7900 XTX on another system however doesn't fare so well.

You could try a 3rd party app too; not sure if SpecialK or the like could work.

Just wanted to warn against the "use Chill" advice I see a lot. It actually doesn't work right.

I'll just leave this here: https: //www.nexusmods.com/fallout4/mods /44798?tab=description

This is a well known engine bug and the linked mod (High FPS Physics Fix) adresses this. Just make sure to use the version 0.8.6 with Fallout London, since the newer versions are only compatible with the next-gen version of FO4.
Read the description on the modpage carefully to make sure everything is installed correctly and you should be good.

(Remove the spaces in the link to access it, the forum won't let me post it otherwise)

I'm using High FPS Physics Fix and it's not working. Gonna try limiting fps to 60 next, which kinda pisses me off because I didn't buy a 4080 to run shit @ 60fps.

But that´s not a fallout london problem, that´s a bethesda engine problem. Fallout 4 shows exactly the same when you don´t limit the frames to 60.

No, it's GOG Fallout problem. High FPS Physics Fix works fine on the old 1.10.163 Steam version which is what I'm playing on now.

This "problem" exists since fallout 4 was released, the difference was that older hardware and older operating systems at that time did conceil it pretty well. So it´s not a "gog" version problem, it´s a problem all versions always had.
Older "High FPS Physics Fix" versions work also on the gog version (i used that here), same counts for the "load accelerator" .dll that is also available and works reliable. The game has to be set to use vsync, the graphics driver has to be set to use the games settings.

I have a hunch here: Mudbass, did you install High FPS Physics Fix as an MO2 mod? F4SE mods installed that way only work with the GOG version of the game if you add "-forcesteamloader" to the arguments for launching F4SE.

I limited my FPS in ENB.

I get too much FPS so i don't use that mod.

Instead i use FO4LoadAccelerator.

You don't even need a Mod Organizer or Vortex to use it.

I capped myself at 60 FPS and i love it.