Hello, rose1. Some of these problems are fungal in nature. They occur when the cane has an injury and fungi infects the plant. This injury can occur after pruning, due to pruning with infected pruners, due to canes rubbing against each others, etc. In these cases, one solution is to remove the infected part of the cane using clean pruners.
I assume that your plant is basically healthy, that you keep the soil moist -never wet-, that there are no minerals defficiencies & pH problems in the soil and that there are no sign of pests like cane borers etc. Is there a chance that you can post a link to a picture(s)?