Yep this is the same problem I have to a T, I hope a fix is found soon :)

Also the same problem for adding or changing nodes sometimes

I was just wondering what the status for this problem is,
I cant use 2.90 efficiently to do texture paint while this bug is there.

I need to do a lot of texture painting atm, but I need to go back and forth a lot because of this problem, I'm using 2.90 (I know its not recommended for production but the sculpt tools and denoisers are just too good, and all is stable for my needs except this issue) so right now my workflow is to use the new sculpt tools at the same time I do some texture paint, and do some rendering with the new denoisers that are only available to 2.90, but I need to switch to 2.83 just to do some of the texture paint, then append the mesh I texture painted to 2.90 and do the sculpting and rendering there, and go back and forth because some times things need changes after they are sculpted in the texture department, so I'm really interested on a solution for this.

I know the devs are busy with a lot of thigs, and I'm grateful for all the cool things Blender has, but in case this bug goes unnoticed... I could really use having this working as soon as possible, Thank you for your time.

Kind Regards.
-Luis

This is the same as T79370: Texture paint does not update during stroke on material and render viewport shading.
Although that report is newer, I will merge into that one (I've already bisected T79370 and found the culprit commit...)