Vertex paint is not rgistering all Vertex after paint for the first time

Development Asset Creation
, , ,
1

After the first paint stroke of Vertex color, it loses some of the vertexes in the mesh (Not all vertexes are missing). this can be rest if I switch to the select mode and then back to the paint mode. is this caused by my material or by the mesh?
341631-
][1]

3

I was having this same issue in UE5 , just switched to UE4.26.2 and its working for me now