Support material detaching from raft

Hi all, my printer seems to have developed an issue where the support material begins detaching from the raft once the support material has reached about 20mm in height. The issue seems to be at the very base of the support material - above this point seems to be fine. The "tower of spport material just gets loose from the raft.

I haven’t been able to find any settings to make the support material heavier. Any ideas appreciated (ps I have recently replaced the FFC extruder cable and this has not fixed the issue. I’m using the UpStudio software v 2.7.3)