Difficulties with wearing a device? discussion

I just received the HTV3 maxi and my initial reaction is that it’s surprisingly comfortable. We had it fitted, checked on things the following day with no issues, and they remained fine two days later, so we opted for a week-long lock-up. Everything went smoothly until day five when I felt a slight stinging between the bottom of the tube and the ring. After tweaking things and moving some skin around, the irritation eased up by day six, but then it returned and didn’t go away despite further adjustments. We took the device out to discover a raw spot on the lower part of the shaft where the tube terminates.

My question is: how do I resolve this? I apply lube both around the ring and when inserting the tube, but once it’s locked in place, that area becomes inaccessible again. Is my body likely to adapt to this over time, or should I be taking specific steps to prevent it?