Thanks. This is the only thing that worked for me.
(Haven’t disabled modelling tools, I’m too addicted to that… 
)
edit: Actually, nothing works. Tried all mentioned tricks, including disabling modeling mode. Hopefully just the editor, haven’t tried a build yet.
Update: Ok so after a day of experimenting it seems not to be possible to disable “Modeling Tools Editor Mode” in UE 5.7. Can anyone else confirm this is the case or am I going crazy? I have tried deleting all temp files / cache /restored from zipped project & removed the entry for the plugin in the .uproject file. Not possible to disable as in, not triggering a chain-reaction disabling a bunch of other core functionality including metahumans.
Also tried renaming the plugin directory in the engine files & moving them out manually, it semi-breaks the modeling plugin but the code seems buil-tin (?) to the engine or something because I can’t get rid of it completely without taking down a bunch of other plugins with it.
Here’s a demo of the problem. (Ignore the camera shake, it’s unrelated; look how far the joystick axis can be slowly pushed all the way to 0.8 before moving). It happens with mouse input too (sticks the same) but shows a lower value in debug because the mouse “unsticks” faster.
To clarify, the above happens randomly (not everytime). Tried making several new Basic Level & spawning the character, it appears completely random if the X-axis gets stuck or not.
I may have solved the issue now by making a different controller BP. I’m not sure what’s going on, if there’s some kind of mismatch in logic / runtime (again since the above happens randomly). Have had strange bugs before with file locations being spread out across the project (the new controller BP is now located in the same as subfolders as the character anim BP.) I’ll update if I learn something more.
Update: Culprit of all seems to have been Player Camera Manager linked to the controller BP. I moved the logic in the camera manager directly into the character BP, and now X-axis works smoothly. (You can still use “get player camera manager node” even if none actually exists). Hopefully helps someone so they don’t have to spend 3 days troubleshooting like me 