As seen in a video, in analog movement mode with Switch Pro controller there is only a minimal input from the left analog stick. When emulating xbox360 controller with it, it works fine other controllers also work fine (i tested dualsense and dualshock). Without analog movement it works fine. I checked if my left stick outputs full range in windows, steam and ds4windows and it does. Also tried the SDL2 mapping and it doesn't change anything.

i cant even get my switch pro to connect to the mod

I tried and it just acts as if the left analog stick was a digital input (0 and some low percent), so if I set it to for example 40% then at first nothing happens and then at some point when pushing the stick suddenly I begin walking, just faster (still not analog movement). Again, camera movement works fine (analog and all) and other controllers work fine too.

Try changing the max value settings in the controller options

That's really weird, I'll try looking into this, but I don't own a Switch Pro controller myself, so idk if I can fix it

While I cannot replicate this specific issue, I've noticed that on a Switch Pro, if the settings are left at default, cardinal directions like forward and strafing reach full speed fine, but diagonals slow to a crawl. This may be because a diagonal cannot be interpreted as max speed while restricted by the controller's circular gate, likely because the mod is interpreting a square gate as maximum input instead. I can't say for sure because there's no graphical test of the mod reading the analog values.

To remedy, I've lowered the dead zone and axis max values, and after this I can reach max speed with some compromise to my range of analog movement. But that's what the Sneak key is for in Minecraft when movement was digital.