I have to eliminate if there is something different with you startup file than my startup file.
Then your brushsettings might have been up to date. Generally the brushstrokes look much too strong in your last screenshot. I agree with @EitanSomething. Save a simple sphere with some lines drawn upon and upload it to pasteall.
In the topright corner of the site there is a button to upload blend files. Copy the link here after that.
I will also drop in later again, but I am in a hurry right now.
What brush were you using
You are experiencing this because the voxel size is too small for the brush that you are using.The are that is affected is also affected by how close you are to the mesh you are editing.
Based on how it looks I assume you’ve used the layer brush. That brush takes the mesh at the beginning of the stroke and adds “material/clay” to your sculpt wherever you paint with a maximum thickness of “height”. You can reduce that height to create thinner layers. Try painting bigger areas before releasing the mouse to get a feel for it.
In that case it’s no wrong behaviour, but if you saw the video with the updated layer brush, that one is indeed not reviewed yet. All code changes have to get reviewed and approved to get into blender. So if that is what you were trying to test you are just ahead of time.
Tried the 2.9 alpha
Things still look ugly at the outset.
Cant understand why the parameters is not set so everything is ok from start
Mic
if i had to guess it’s because you downloaded the latest nightly build of a development branch of alpha software. no offense, but it sounds like you need to take a year or two off from Blender and come back when the dust settles and some of these features that are still in development land in a public release? Blender has only just started becoming palatable for the ‘average user’ within the past year or so, I think you’re expecting too much so soon.