I have 43 settlers in Sanctuary with a very large build and have recently noticed that when I move around in the settlement it is very glitch and not smooth...so as an experiment I went to another settlement that has 25 settlers with hardly any building and SMOOTH movement...has anyone experienced this and how to fix? Do I need to scrap builds and move settlers to another location? What is the best number of settlers to have in a settlement?
How in the world do you have 43 settlers in Sanctuary? The most settlers I've ever had in a settlement is 23, and that's with a maxed out charisma. Are you on PC using mods by any chance? It sounds like there's too much stuff in your Sanctuary for the game to render smoothly. I'd try moving some settlers to somewhere else or turning them into supply lines.
Playing on Xbox One wit NO MODS. Have max Charisma and you wear clothing with Charisma (have Agatha Dress for 3 Char and you wear a hat that has Char...then before you move a settler take a consumable with Char too)...got rid of the glitchyness by scrapping some builds I had in Sanctuary..no it's fine still have 42 settlers.
The main reason as others have stated is that you have too many settlers and it is cramping up your game. Try relocating them and have 2 twenty people settlements.
The game was glitchy for me as well when I had too many settlers, try relocating some and then give it another go, that fixed it for me.
It's to be expected, Bethesda has a hard time optimizing their games. As others have said, try moving around your settlers and see if that helps the issue.