What you have is a classic case of bromide drag. This is the result of underagitation. It can also be caused by the wrong developer for the conditions.
Bromide is an antifoggant and is heavy so it drifts downwards and restrains the development in a path down from dark areas. OTOH, some development byproducts either speed up or slow down development and they too can alter development in ghostly patterns. Agitation disperses any and all of these byproducts and prevents them from causing the marks you are seeing.
Stand can be done, but it is an art that is learned just like any other art.