Invasive Notifications

I am trying to use nextcloud android app to be able to regularly or automatically backup a specific folder on my mobile to an encrypted nextcloud provider. It seem to work. However from times to times the app will throw at me dozens of notifications about some file conflict that I should resolve even though I configured it to erase the distant version by default. Why does the nextcloud android app regularly invade my notification space and try to sync the whole folder asking me to choose versions when I specifically told it to erase distant file by dedaut?